Dusseldorf, Germany (CNN) Analysis of a tablet device belonging to Germanwings Flight 9525 co-pilot Andreas Lubitz shows he researched suicide methods on the Internet in the days leading up to the crash, a German prosecutor said Thursday. 
 
 Dusseldorf prosecutor Christoph Kumpa said that on one day Lubitz also "searched for several minutes with search terms relating to cockpit doors and their security measures." 
 
 Police analysis of the correspondence and search history on the device, retrieved from Lubitz's Dusseldorf apartment, demonstrated that the co-pilot used it from March 16 to March 23, Kumpa said. 
 
 The search history was not deleted and also revealed searches concerning medical treatment, the prosecutor said. 
 
 Lubitz is suspected of deliberately bringing down Germanwings Flight 9525 in the French Alps on March 24, killing all 150 on board. Investigators have since focused on his health as they try to establish his motivation. 
 
 Noting he's made a criminal request to German authorities but is for now conducting his own investigation, the prosecutor in Marseille, France, said he is tasked with an involuntary homicide investigation. But prosecutor Brice Robin noted that Lubitz made voluntary actions -- such as guiding the plane toward the mountain and reducing its speed to prevent alarms from going off -- and was "alive and conscious" to the very end. 
 
 A European official government official with detailed knowledge of the investigation said that Lubitz's actions amount to"premeditated murder." 
 
 While cautioning that there are still many holes in understanding Lubitz's motivation, the disclosures about his Internet searches show that he planned to do what he was going to do, according to this official. 
 
 Second 'black box' found 
 
 As authorities try to figure out what was on Lubitz's electronic devices, they got another big break about what was happening inside Airbus 320 that went down -- its flight data recorder. 
 
 The jetliner's cockpit voice recorder was located shortly after the plane crashed. Now, investigators have both "black boxes," as the devices are called, and the details that they might provide. 
 
 A female police officer digging by hand for clothes in a ravine that been searched previously found the flight data recorder on Thursday afternoon about 8 inches (20 centimeters) below the surface, Robin told reporters. 
 
 Normally white with florescent orange, this discovered recorder lived up to its name as a black box because fire had darkened it with ashes. Even with this damage, the Marseille prosecutor said that investigators should be able to get useful information out of it. 
 
 "We will be able to identify the speed, the altitude and the way the pilot acted ... which will be critical," said Robin. 
 
 Prosecutor: 150 sets of DNA recovered 
 
 The voice data recorder is one of many items uncovered at the crash site in the southern French Alps. 
 
 Authorities have found 470 personnel effects there, according to Robin. That number includes 40 cell phones, though all those were badly damaged. Robin cast doubt that any useful information could be retrieved from those phones, given their condition. 
 
 JUST WATCHED French reporter says he's seen Germanwings video Replay More Videos ... MUST WATCH French reporter says he's seen Germanwings video 03:06 
 
 This is consistent with French officials' claims Wednesday insisting that two publications, German daily Bild and French Paris Match, were wrong to report that cell phone video showed the harrowing final seconds from on board the flight. 
 
 More importantly, investigators have isolated 150 different sets of DNA -- a number that corresponds with the number of people on Flight 9525. Still, the Marseille prosecutor cautioned, "It doesn't mean we have identified 150 victims. We need to compare (the recovered DNA to) DNA from the families and the deceased." 
 
 Robin estimated "it will take between three to five weeks, if all goes well" for the passengers' loved ones to get the remains. 
 
 But the mourning is already underway. 
 
 A memorial stone set up in the village of Le Vernet, the nearest accessible point to the crash site, has become a place of pilgrimage for those with relatives and friends on board the plane. 
 
 People in the German town of Haltern recently came together for a memorial service to remember 16 students and two teachers lost in the crash. 
 
 JUST WATCHED Small German town remembers crash victims Replay More Videos ... MUST WATCH Small German town remembers crash victims 02:54 
 
 Push to take steps to prevent a repeat 
 
 Providing some closures to the families of those passengers and crew members is a top priority for authorities. 
 
 So, too, is doing what they can to figure out why this happened and prevent similar tragedies. 
 
 There are new calls from aviation experts to develop and deploy enhanced crash avoidance software that could take control of an aircraft away from a pilot and steer it to a safe altitude. 
 
 Photos: Germanwings plane crashes in France Photos: Germanwings plane crashes in France A recovery crew works among debris of Germanwings Flight 9525 at the crash site near Seyne-les-Alpes, France, on Friday, April 3. The crash killed all 150 people aboard and has raised questions about the co-pilot's mental state. Hide Caption 1 of 26 Photos: Germanwings plane crashes in France French Gen. David Galtier holds up a picture of the second black box from Germanwings 9525 during a news conference in Marseille, France, on Thursday, April 2. The flight data recorder shows that co-pilot Andreas Lubitz purposely used the controls to speed up the plane's descent, investigators said. Hide Caption 2 of 26 Photos: Germanwings plane crashes in France Rescue workers recover debris from the crash site in the French Alps on Tuesday, March 31. Flight 9525 was traveling from Barcelona, Spain, to Dusseldorf, Germany, when it crashed. Hide Caption 3 of 26 Photos: Germanwings plane crashes in France A helicopter drops rescue workers next to crash debris near Seyne-les-Alpes, France, on Sunday, March 29. Hide Caption 4 of 26 Photos: Germanwings plane crashes in France Forensic experts work near the crash site on Thursday, March 26. Hide Caption 5 of 26 Photos: Germanwings plane crashes in France Journalists stand in front of the Westerwald airfield in Montabaur, Germany, on March 27. Lubitz reportedly learned to fly here. Hide Caption 6 of 26 Photos: Germanwings plane crashes in France Investigators carry a computer from the home of Lubitz's parents in Montabaur, Germany, on Thursday, March 26. Hide Caption 7 of 26 Photos: Germanwings plane crashes in France A police officer stands guard March 26 at an apartment building where Lubitz was thought to have lived in Dusseldorf. Hide Caption 8 of 26 Photos: Germanwings plane crashes in France A helicopter lifts a rescue worker from the crash site on March 26. Hide Caption 9 of 26 Photos: Germanwings plane crashes in France Rescue workers continue to search the site of the crash on March 26. Hide Caption 10 of 26 Photos: Germanwings plane crashes in France Search-and-rescue teams land near the crash site on Wednesday, March 25. Hide Caption 11 of 26 Photos: Germanwings plane crashes in France Debris from the plane is seen along a mountainside on March 25. Hide Caption 12 of 26 Photos: Germanwings plane crashes in France French military personnel move up a mountainside March 25 near Seyne-les-Alpes. Hide Caption 13 of 26 Photos: Germanwings plane crashes in France The cockpit voice recorder of the Germanwings jet appears in this photo provided by the French air accident investigation bureau on March 25. The device is designed to capture all sounds on a plane's flight deck. Hide Caption 14 of 26 Photos: Germanwings plane crashes in France A helicopter comes in to land near Seyne-les-Alpes, the staging ground for search efforts, on March 25. Hide Caption 15 of 26 Photos: Germanwings plane crashes in France Rescue workers and members of the French Gendarmerie gather in Seyne-les-Alpes on Tuesday, March 24, as search-and-rescue teams struggle to reach the remote crash. Hide Caption 16 of 26 Photos: Germanwings plane crashes in France Wreckage is seen at the crash site on March 24. Hide Caption 17 of 26 Photos: Germanwings plane crashes in France Response teams gather in Seyne-les-Alpes on March 24. Hide Caption 18 of 26 Photos: Germanwings plane crashes in France Relatives of the flight's passengers arrive at the airport in Barcelona on March 24. Hide Caption 19 of 26 Photos: Germanwings plane crashes in France People hold hands walking through the Dusseldorf Airport on March 24. Hide Caption 20 of 26 Photos: Germanwings plane crashes in France The arrivals board at the Dusseldorf Airport shows Germanwings Flight 9525 without a status on March 24. Hide Caption 21 of 26 Photos: Germanwings plane crashes in France People arrive at the Dusseldorf Airport on March 24. Hide Caption 22 of 26 Photos: Germanwings plane crashes in France An employee of Swissport, the handling agent of Germanwings flights from Barcelona, speaks by phone at the Barcelona-El Prat Airport on March 24. Hide Caption 23 of 26 Photos: Germanwings plane crashes in France Relatives of people involved in the crash arrive at the Barcelona airport on March 24. Hide Caption 24 of 26 Photos: Germanwings plane crashes in France A man in Madrid looks at a monitor with a map, released from the Flightradar24 website, showing the point where the plane's radar signal went missing. Hide Caption 25 of 26 Photos: Germanwings plane crashes in France This undated file photo shows the Germanwings Airbus A320 that crashed. Germanwings is a low-cost airline owned by the Lufthansa Group. Hide Caption 26 of 26 
 
 The idea is not new. In fact more than 10 years ago following 9/11, Airbus, the manufacturer of the doomed aircraft, was working to d‎evelop aircraft crash avoidance software with tech giant Honeywell -- in part to prevent jetliners from being flown into large buildings or mountains. But the project was ultimately scrapped. 
 
 Still, there's also a widespread view that the best way to understand what happened in this case is to understand Lubitz. 
 
 Source: Lubitz saw multiple doctors 
 
 It is becoming increasingly clear to investigators that Lubitz was "very afraid" he would lose his license to fly because of his medical issues, a law enforcement source with detailed knowledge of the investigation told CNN. 
 
 It's already emerged that Lubitz had battled depression years before he took the controls of Flight 9525 and that he had concealed from his employer recent medical leave notes saying he was unfit for work. 
 
 But the law enforcement source said that after a severe depressive episode in 2009, Lubitz relapsed with severe depression and stress in late 2014. 
 
 In the weeks leading up to the crash, Lubitz was shopping doctors, seeing at least five, perhaps as many as six, the source said, as he kept going from one doctor to the next seeking help. 
 
 The 27-year-old was having trouble sleeping, and one of the doctors he saw recently was a sleep specialist, the law enforcement source said. Lubitz apparently told some doctors that he was afraid of losing his pilot's license because of his medical issues. 
 
 The doctors knew he was a pilot and gave him a "not fit to work" notice, which he was apparently required to give to his employer, even though he didn't, the source said. Officials have found doctors handled the matter the way they were supposed to and found no negligence on their part. 
 
 Thinking he would stay home from work based on the sick notes, Lubitz was prescribed a lot of medication, including "heavy depression medicine" that would have been "very heavy" on the body and "critical to a pilot," the source said. 
 
 However, the law enforcement source doesn't think Lubitz was using the medicine while working, because investigators interviewed a pilot he flew with the day before who said he was "completely normal" with no problem whatsoever. 
 
 Inside Lubitz's apartment, investigators found a couple of notes with only a few words, involving stress and his pilot's license, the source added. He didn't know if Lubitz wrote these down while talking to someone on the phone or wrote the memo to remind himself of something. 
 
 JUST WATCHED Prosecutors: Co-pilot suicidal at one time Replay More Videos ... MUST WATCH Prosecutors: Co-pilot suicidal at one time 00:10 
 
 Lubitz told his Lufthansa flight training school in 2009 that he had a "previous episode of severe depression," the German airline confirmed Tuesday. Lufthansa is the parent company of budget airline Germanwings. 
 
 Confidentiality issues 
 
 German officials announced that a new task force would look at issues including medical procedures for pilots and cockpit door locking mechanisms after the devastating crash. 
 
 The cockpit voice recorder revealed that Lubitz had locked the pilot, Patrick Sondenheimer , out of the cockpit before putting the plane into its fatal descent, said Robin, the Marseille prosecutor. 
 
 Cockpit doors on planes were strengthened following the events of September 11, 2001, making it impossible for the captain to force his way in. 
 
 German Transport Minister Alexander Dobrindt told the news conference Thursday that the task force would prioritize questions around the cockpit door locking mechanism and procedures for checking pilots' medical and psychological well-being. 
 
 It would seek to move quickly, he said, but would not make rash decisions. 
 
 Klaus-Peter Siegloch, head of the German Aviation Association, emphasized issues around confidentiality when it comes to a pilot's medical records. 
 
 "The confidence our pilots have in our medical doctors is of high importance," he said. "I believe if there is a lifting of doctor-patient confidentiality, then possibly pilots will not trust in medical doctors and that will make the situation worse." 
 
 The task force will bring together government officials with representatives of the German airline companies, the German Aviation Association and the Federation of German Airlines. ||||| Dusseldorf, Germany (CNN) Years before he was at the controls of a Germanwings plane that plunged into the French Alps, Andreas Lubitz told the airline he worked for that he'd had a bout with depression. 
 
 Lubitz, the co-pilot of Germanwings Flight 9525 who authorities accuse of deliberately crashing the plane, told his Lufthansa flight training school in 2009 that he had a "previous episode of severe depression," the airline said Tuesday. 
 
 Email correspondence between Lubitz and the school discovered in an internal investigation, Lufthansa said, included medical documents he submitted in connection with resuming his flight training. 
 
 The announcement indicates that Lufthansa, the parent company of Germanwings, knew of Lubitz's battle with depression, allowed him to continue training and ultimately put him in the cockpit. 
 
 Lufthansa, whose CEO previously said Lubitz was 100% fit to fly, described its statement Tuesday as a "swift and seamless clarification" and said it was sharing the information and documents -- including training and medical records -- with public prosecutors. 
 
 It's a development that will likely be a part of the crash investigation, but it's only one piece of the puzzle, CNN aviation correspondent Richard Quest said. 
 
 "We need to know what happened after he returned in 2009 and finished his training, because that tells us whether there was the correct procedure and process," he said. 
 
 A Lufthansa spokesperson told CNN on Tuesday that Lubitz had a valid medical certificate, had passed all his examinations and "held all the licenses required." 
 
 JUST WATCHED Prosecutors: Co-pilot suicidal at one time Replay More Videos ... MUST WATCH Prosecutors: Co-pilot suicidal at one time 00:10 
 
 Possible motive: Fear of losing license 
 
 The details about Lubitz's correspondence with the flight school during his training were among several developments as investigators continued to delve into what caused the crash and Lubitz's possible motive for downing the jet. 
 
 Earlier, a spokesman for the prosecutor's office in Dusseldorf said Lubitz suffered from suicidal tendencies at some point before his aviation career. 
 
 Medical records reveal that Lubitz was suicidal at one time and underwent psychotherapy before he got his pilot's license, prosecutor's spokesman Christoph Kumpa said. 
 
 Kumpa emphasized there's no evidence suggesting Lubitz was suicidal or acting aggressively before the crash. 
 
 Investigators are looking into whether Lubitz feared his medical condition would cause him to lose his pilot's license, a European government official briefed on the investigation into last week's crash told CNN on Tuesday. 
 
 While flying was "a big part of his life," the source said, it's only one theory being considered. 
 
 Another source, a law enforcement official briefed on the investigation, also told CNN that authorities believe the primary motive for Lubitz to bring down the plane was that he feared he would not be allowed to fly because of his medical problems. 
 
 Lubitz's girlfriend told investigators he had seen an eye doctor and a neuropsychologist, both of whom deemed him unfit to work recently and concluded he had psychological issues, the European government official said. 
 
 Lubitz told the neuropsychologist that he was too stressed with work, the official said. 
 
 But no matter what details emerge about his previous mental health struggles, there's more to the story, said Brian Russell, a forensic psychologist. 
 
 "Psychology can explain why somebody would turn rage inward on themselves about the fact that maybe they weren't going to keep doing their job and they're upset about that and so they're suicidal," he said. "But there is no mental illness that explains why somebody then feels entitled to also take that rage and turn it outward on 149 other people who had nothing to do with the person's problems." 
 
 Video of flight's final seconds? 
 
 Reports say a cell phone video shows the nightmarish final seconds of Germanwings Flight 9525, but a police spokesman said the accounts were "completely wrong." 
 
 French magazine Paris Match and German newspaper Bild reported that a video recovered from a phone at the wreckage site showed the inside of the plane moments before it crashed. 
 
 "One can hear cries of 'My God' in several languages," Paris Match reported . "Metallic banging can also be heard more than three times, perhaps of the pilot trying to open the cockpit door with a heavy object. Towards the end, after a heavy shake, stronger than the others, the screaming intensifies. Then nothing." 
 
 The two publications described the video, but did not post it on their websites. The publications reported that they watched the video, which was found by a source close to the investigation. 
 
 "It is a very disturbing scene," said Julian Reichelt, editor-in-chief of Bild online. 
 
 An official with France's accident investigation agency, the BEA, said the agency is not aware of any such video. 
 
 Lt. Col. Jean-Marc Menichini, a French Gendarmerie spokesman in charge of communications on rescue efforts around the Germanwings crash site, told CNN that the reports were "completely wrong" and "unwarranted." Cell phones have been collected at the site, he said, but that they "hadn't been exploited yet." 
 
 Menichini said he believed the cell phones would need to be sent to the Criminal Research Institute in Rosny sous-Bois, near Paris, in order to be analyzed by specialized technicians working hand-in-hand with investigators. But none of the cell phones found so far have been sent to the institute, Menichini said. 
 
 Asked whether staff involved in the search could have leaked a memory card to the media, Menichini answered with a categorical "no." 
 
 Reichelt told "Erin Burnett: Outfront" that he had watched the video and stood by the report, saying Bild and Paris Match are "very confident" that the clip is real. 
 
 He noted that investigators only revealed they'd recovered cell phones from the crash site after Bild and Paris Match published their reports. 
 
 "That is something we did not know before. ... Overall we can say many things of the investigation weren't revealed by the investigation at the beginning," he said. 
 
 Recovery efforts continue 
 
 While investigators search for clues to Lubitz's motivation, recovery workers continue the grim task of searching for the remains of those killed in the March 24 crash. 
 
 The remains of at least 78 people on board the plane have been identified so far using DNA analysis. 
 
 Naffrechoux warned Monday that "it may not be possible to find the human remains of all the 150 passengers, as some of them may have been pulverized by the crash." 
 
 But French President Francois Hollande, speaking alongside German Chancellor Angela Merkel in Berlin, was more positive, saying that it should be possible to identify all the victims by the end of the week. 
 
 Photos: Germanwings plane crashes in France Photos: Germanwings plane crashes in France A recovery crew works among debris of Germanwings Flight 9525 at the crash site near Seyne-les-Alpes, France, on Friday, April 3. The crash killed all 150 people aboard and has raised questions about the co-pilot's mental state. Hide Caption 1 of 26 Photos: Germanwings plane crashes in France French Gen. David Galtier holds up a picture of the second black box from Germanwings 9525 during a news conference in Marseille, France, on Thursday, April 2. The flight data recorder shows that co-pilot Andreas Lubitz purposely used the controls to speed up the plane's descent, investigators said. Hide Caption 2 of 26 Photos: Germanwings plane crashes in France Rescue workers recover debris from the crash site in the French Alps on Tuesday, March 31. Flight 9525 was traveling from Barcelona, Spain, to Dusseldorf, Germany, when it crashed. Hide Caption 3 of 26 Photos: Germanwings plane crashes in France A helicopter drops rescue workers next to crash debris near Seyne-les-Alpes, France, on Sunday, March 29. Hide Caption 4 of 26 Photos: Germanwings plane crashes in France Forensic experts work near the crash site on Thursday, March 26. Hide Caption 5 of 26 Photos: Germanwings plane crashes in France Journalists stand in front of the Westerwald airfield in Montabaur, Germany, on March 27. Lubitz reportedly learned to fly here. Hide Caption 6 of 26 Photos: Germanwings plane crashes in France Investigators carry a computer from the home of Lubitz's parents in Montabaur, Germany, on Thursday, March 26. Hide Caption 7 of 26 Photos: Germanwings plane crashes in France A police officer stands guard March 26 at an apartment building where Lubitz was thought to have lived in Dusseldorf. Hide Caption 8 of 26 Photos: Germanwings plane crashes in France A helicopter lifts a rescue worker from the crash site on March 26. Hide Caption 9 of 26 Photos: Germanwings plane crashes in France Rescue workers continue to search the site of the crash on March 26. Hide Caption 10 of 26 Photos: Germanwings plane crashes in France Search-and-rescue teams land near the crash site on Wednesday, March 25. Hide Caption 11 of 26 Photos: Germanwings plane crashes in France Debris from the plane is seen along a mountainside on March 25. Hide Caption 12 of 26 Photos: Germanwings plane crashes in France French military personnel move up a mountainside March 25 near Seyne-les-Alpes. Hide Caption 13 of 26 Photos: Germanwings plane crashes in France The cockpit voice recorder of the Germanwings jet appears in this photo provided by the French air accident investigation bureau on March 25. The device is designed to capture all sounds on a plane's flight deck. Hide Caption 14 of 26 Photos: Germanwings plane crashes in France A helicopter comes in to land near Seyne-les-Alpes, the staging ground for search efforts, on March 25. Hide Caption 15 of 26 Photos: Germanwings plane crashes in France Rescue workers and members of the French Gendarmerie gather in Seyne-les-Alpes on Tuesday, March 24, as search-and-rescue teams struggle to reach the remote crash. Hide Caption 16 of 26 Photos: Germanwings plane crashes in France Wreckage is seen at the crash site on March 24. Hide Caption 17 of 26 Photos: Germanwings plane crashes in France Response teams gather in Seyne-les-Alpes on March 24. Hide Caption 18 of 26 Photos: Germanwings plane crashes in France Relatives of the flight's passengers arrive at the airport in Barcelona on March 24. Hide Caption 19 of 26 Photos: Germanwings plane crashes in France People hold hands walking through the Dusseldorf Airport on March 24. Hide Caption 20 of 26 Photos: Germanwings plane crashes in France The arrivals board at the Dusseldorf Airport shows Germanwings Flight 9525 without a status on March 24. Hide Caption 21 of 26 Photos: Germanwings plane crashes in France People arrive at the Dusseldorf Airport on March 24. Hide Caption 22 of 26 Photos: Germanwings plane crashes in France An employee of Swissport, the handling agent of Germanwings flights from Barcelona, speaks by phone at the Barcelona-El Prat Airport on March 24. Hide Caption 23 of 26 Photos: Germanwings plane crashes in France Relatives of people involved in the crash arrive at the Barcelona airport on March 24. Hide Caption 24 of 26 Photos: Germanwings plane crashes in France A man in Madrid looks at a monitor with a map, released from the Flightradar24 website, showing the point where the plane's radar signal went missing. Hide Caption 25 of 26 Photos: Germanwings plane crashes in France This undated file photo shows the Germanwings Airbus A320 that crashed. Germanwings is a low-cost airline owned by the Lufthansa Group. Hide Caption 26 of 26 
 
 A simple stone memorial has been set up at Le Vernet, where grieving relatives of those killed have laid flowers and held prayers. 
 
 Safety investigation 
 
 The BEA, France's accident investigation agency, said its ongoing safety investigation was focusing on a more detailed analysis of the flight history leading up to the crash, based on the audio recovered from the cockpit voice recorder and any other available data. 
 
 "A deliberate act by a man with a disturbed psychological profile is a possible scenario," BEA spokeswoman Martine Del Bono told CNN. "The first step of the investigation is to describe more precisely what happened." 
 
 This will be based mainly on analysis of the cockpit voice recorder, to be supplemented by data from the flight data recorder if it is found, she said. 
 
 "But we will also look at other events with possibly similar scenarios, try to understand if there are systemic weaknesses which may contribute or facilitate such scenarios. 
 
 "We will in particular look at the cockpit door locking as well as the criteria and procedures applied to detect specific psychological profiles." ||||| Image copyright AFP Image caption The German tabloid Bild carried an interview with the ex-girlfriend of Germanwings co-pilot Andreas Lubitz (pictured) 
 
 The Germanwings co-pilot thought to have deliberately crashed his Airbus in the French Alps, killing 150 people, predicted "one day everyone will know my name", his ex-girlfriend says. 
 
 In an interview with Germany's Bild newspaper, she recalled a comment Andreas Lubitz made last year. 
 
 "One day I'm going to do something that will change the whole system, and everyone will know my name and remember," he told her. 
 
 Flight 4U 9525 crashed on Tuesday. 
 
 The woman, a 26-year-old flight attendant who flew with Lubitz for five months last year, was "very shocked" when she heard the news, the paper says. 
 
 She is referred to only as Maria W. 
 
 Image copyright AP Image caption Memorial services for those onboard flight 4U 9525 have been taking place in Germany and in Spain 
 
 If Lubitz deliberately brought down the plane, "it is because he understood that because of his health problems, his big dream of a job at Lufthansa, as captain and as a long-haul pilot was practically impossible," she told Bild. 
 
 Meanwhile, German newspaper Die Welt said that investigators had found evidence of a serious "psychosomatic illness", and that Lubitz had been "treated by several neurologists and psychiatrists". 
 
 Several medicines used to treat mental illnesses were found at his home, but there were no signs of drug or alcohol addiction, the newspaper, citing an unnamed investigator, said. 
 
 Separately, the New York Times, citing officials, reported that Lubitz had sought treatment for eye problems. 
 
 Briton's father in plea to airlines 
 
 'Too much pressure' 
 
 French investigator Jean-Pierre Michel also told the AFP news agency that the pilot's personality was "a serious lead [in the investigation] but... can't be the only one". 
 
 "We're going to try to understand what in his life could have left him to carry out the act," Mr Michel said, adding that investigators had not discovered any "particular element" so far. 
 
 The black box voice recorder indicates that Lubitz locked his captain out of the cockpit on Tuesday and crashed the plane into a mountainside in what appears to have been a suicide and mass killing. 
 
 Image copyright AFP Image caption Lufthansa and Germanwings took out full-page condolence notices in German newspapers 
 
 German prosecutors say they found medical documents at Lubitz's house suggesting an existing illness and evidence of medical treatment. They found torn-up sick notes, one of them for the day of the crash. 
 
 They say he seems to have concealed his illness from his employers. 
 
 His former girlfriend told Bild they separated, "because it became increasingly clear that he had a problem". 
 
 Media playback is unsupported on your device Media caption Ex-girlfriend: "He sometimes tended to be aggressive" 
 
 She said he was plagued by nightmares and would at times wake up screaming "we're going down". 
 
 She added that he became stressed when they spoke about work: "He became upset about the conditions we worked under: too little money, fear of losing the contract, too much pressure." 
 
 A hospital in the German city of Duesseldorf has confirmed Lubitz was a patient there recently but it denied media reports that he had been treated for depression. 
 
 Lubitz's employers insisted that he had only been allowed to resume training after his suitability was "re-established". 
 
 Image copyright Getty Images Image caption Andreas Lubitz running a half-marathon in Frankfurt in March 2010 
 
 Lubitz's health timeline 
 
 2009 : Breaks off pilot training while still in his early twenties after suffering "depressions and anxiety attacks", the German tabloid Bild reports, quoting Lufthansa medical files. Resumes training after 18 months of treatment, according to Bild 
 
 : Breaks off pilot training while still in his early twenties after suffering "depressions and anxiety attacks", the German tabloid Bild reports, quoting Lufthansa medical files. Resumes training after 18 months of treatment, according to Bild 2013 : Qualifies "with flying colours" as pilot, according to Lufthansa 
 
 : Qualifies "with flying colours" as pilot, according to Lufthansa 2013-2015 : Medical file quoted by Bild marks him as requiring "specific regular medical examination" but no details are given 
 
 : Medical file quoted by Bild marks him as requiring "specific regular medical examination" but no details are given February 2015 : Undergoes diagnosis at Duesseldorf University Clinic for an unspecified illness; clinic has clarified the illness was not depression 
 
 : Undergoes diagnosis at Duesseldorf University Clinic for an unspecified illness; clinic has clarified the illness was not depression 10 March 2015 : Again attends Duesseldorf University Clinic 
 
 : Again attends Duesseldorf University Clinic 24 March 2015 :Is believed to have deliberately crashed airliner, killing himself and 149 others 
 
 :Is believed to have deliberately crashed airliner, killing himself and 149 others 26 March 2015: Prosecutors announce that two sick notes have been found torn up at his addresses in Germany 
 
 Unanswered questions 
 
 What drives people to murder-suicide? 
 
 Who was Andreas Lubitz? 
 
 'Unfathomable loss' 
 
 A fellow member of the flight school where Andreas Lubitz took lessons told the BBC the co-pilot had known the area of the French Alps where the plane crashed from going there on gliding holidays. 
 
 A French newspaper, Metro News, reported (in French) that Lubitz had holidayed with his parents at a flying club nearby. 
 
 French police say the search for passenger remains and debris on the mountain slopes could take another two weeks. 
 
 Media playback is unsupported on your device Media caption Relatives have been visiting the site of the Alps plane crash 
 
 Relatives of some of the passengers and crew who died, including the family of the captain, have visited Seyne-les-Alpes, near the crash site. 
 
 In the aftermath of the crash, the EU's aviation regulator, the European Aviation Safety Agency, has urged airlines to adopt new safety rules. 
 
 In future, it says, two crew members should be present in the cockpit at all times. 
 
 Lufthansa and Germanwings have taken out full-page notices in German newspapers, expressing their "deepest sympathy" and condolences for "the unfathomable loss of 150 lives". 
 
 What is depression? 
 
 Depression is more than just feeling a bit down for a few days. It is an illness which, at its most severe, can leave people feeling that life is no longer worth living. It can cause physical symptoms such as headaches, sleeplessness and constant tiredness which may last for months and months. 
 
 People with depression can also feel anxious, irritable and agitated on a daily basis but it affects everyone differently and only in rare cases is it a reason for violence against others. 
 
 If people admit their symptoms and talk to someone about their feelings, depression can usually be treated but the biggest barrier to getting help is often stigma and the fear of disclosing mental health problems. 
 
 German media examine 'depression' reports 
 
 Headlines add to stigma for sufferers 
 
 More on depression 
 
 Other incidents thought to be caused by deliberate pilot action 
 
 29 November 2013: A flight between Mozambique and Angola crashed in Namibia, killing 33 people. Initial investigation results suggested the accident was deliberately carried out by the captain shortly after the first officer (also known as the co-pilot) had left the flight deck. 
 
 A flight between Mozambique and Angola crashed in Namibia, killing 33 people. Initial investigation results suggested the accident was deliberately carried out by the captain shortly after the first officer (also known as the co-pilot) had left the flight deck. 31 October 1999: An EgyptAir Boeing 767 went into a rapid descent 30 minutes after taking off from New York, killing 217 people. An investigation suggested that the crash was caused deliberately by the relief first officer but the evidence was not conclusive. 
 
 An EgyptAir Boeing 767 went into a rapid descent 30 minutes after taking off from New York, killing 217 people. An investigation suggested that the crash was caused deliberately by the relief first officer but the evidence was not conclusive. 19 December 1997: More than 100 people were killed when a Boeing 737 travelling from Indonesia to Singapore crashed. The pilot - suffering from "multiple work-related difficulties" - was suspected of switching off the flight recorders and intentionally putting the plane into a dive. 
 
 Source: Aviation Safety Network ||||| (CNN) German investigators found antidepressants in the apartment of Germanwings co-pilot Andreas Lubitz this week, according to published reports. 
 
 Die Welt, a German newspaper, cited an unidentified senior investigator who said Lubitz suffered from a severe "psychosomatic illness" and German police seized prescription drugs that treat the condition. Lubitz suffered from a "severe subjective burnout syndrome" and from severe depression, the source told Die Welt. 
 
 The New York Times also reported that antidepressants were found during the search of his apartment. CNN has not been able to confirm the reports. 
 
 Investigators continued to work Saturday to piece together the secret life of Lubitz, who officials say was hiding an illness from his employers. He had been declared "unfit to work" by a doctor. 
 
 They were expected to question his relatives, friends and co-workers as they try to pin down what could have prompted the seemingly competent and stable co-pilot to steer a jetliner into a mountainside on Tuesday. 
 
 As their efforts continued, dozens of people attended a remembrance ceremony for the victims of the crash at a church in a nearby town, Digne-les-Bains. There were 150 people on board Germanwings Flight 9525, including Lubitz. 
 
 Relatives of the victims and local residents also gathered Saturday afternoon by a simple stone memorial set up near the crash site, in the village of Le Vernet. Flowers have been laid there, in the shadow of the snow-covered peaks of the French Alps. 
 
 JUST WATCHED Police search Germanwings co-pilot's home for clues Replay More Videos ... MUST WATCH Police search Germanwings co-pilot's home for clues 00:10 
 
 Mental health speculation 
 
 Much attention has focused on Lubitz's state of mind, with some media reports speculating that he may have had mental health issues. 
 
 Investigators found a letter in the waste bin of his Dusseldorf, Germany, apartment saying that Lubitz, 27, wasn't fit to do his job, city prosecutor Christoph Kumpa said Friday. The note, Kumpa said, had been "slashed." 
 
 Just what was ailing Lubitz hasn't been revealed. The New York Times and the Wall Street Journal, citing unnamed sources, reported Friday that Lubitz suffered from mental illness and kept his diagnosis concealed from his employer. 
 
 A subsequent New York Times report on Saturday, citing two officials with knowledge of the investigation, said Lubitz sought treatment before the crash for vision problems that might have put his career at risk. According to those unnamed officials, Lubitz also was being treated for psychological issues. Other media reports indicate he was treated for depression. 
 
 Lubitz passed his annual pilot recertification medical examination in summer 2014, a German aviation source told CNN. 
 
 An official with Lufthansa, which owns Germanwings, said the exam only tests physical health, not psychological health, and that if Lubitz had vision problems that would have been discovered during the tests. 
 
 "We can't believe it. If anything was wrong with his eyes during the physical exam we would have known," the official says. 
 
 The Lufthansa official also said the company was never given any indication Lubitz was depressed, and that if he went to a doctor on his own he would have been required to self-report if he had been deemed unfit to fly. 
 
 A Dusseldorf clinic said he'd gone there twice, most recently on March 10, "concerning a diagnosis." But the University Clinic said it had not treated Lubitz for depression. 
 
 German investigators said they still have interviews and other work to do before they can reveal what they gleaned from the records found in the apartment and at his parents' home in the town of Montabaur. 
 
 JUST WATCHED Prosecutor: Co-pilot hid 'illness' from airline Replay More Videos ... MUST WATCH Prosecutor: Co-pilot hid 'illness' from airline 02:40 
 
 But the fact that investigators found "ripped, recent medical leave notes, including for the day of the offense, leads to the preliminary conclusion that the deceased kept his illness secret from his employer and his professional environment," prosecutors said. 
 
 Germanwings corroborated that assertion, saying it had never received a sick note from Lubitz. 
 
 Authorities left Lubitz's apartment Friday night with boxes of papers and evidence folders after spending about 90 minutes inside. 
 
 Investigators exchange information 
 
 Dusseldorf police said Saturday that a small team of French investigators had arrived in the city and that they were sharing information. 
 
 Jean Pierre Michel, lead investigator for the French inquiry, told French TV from Dusseldorf that the French team would work in "full transparency" with their German counterparts. 
 
 "We will interview people related to the investigation in the coming days. The hearings will be conducted in the coming days and weeks," he said, according to CNN's French affiliate BFMTV. 
 
 Asked by a journalist about reports of Lubitz's possible mental illness, he replied: "The elements of the investigation are strictly confidential and we cannot address these matters today." 
 
 No scenario can yet be ruled out, including mechanical failure, "as we do not have the necessary evidence," he said. 
 
 The German tabloid newspaper Bild said Saturday it had interviewed an ex-girlfriend of Lubitz. The woman is not named in the story and CNN has not been able to verify the report independently. 
 
 According to Bild, the ex-girlfriend said Lubitz was a very nice and sensitive man who needed a lot of care and attention, and he was very troubled. She said he would get into fights with her. 
 
 The newspaper also cited the ex-girlfriend as saying that Lubitz had bad dreams that his plane was going down. 
 
 Relative names flight captain 
 
 Patrick Sondenheimer was the pilot of Germanwings Flight 9525, according to Reiner Sondenheimer of Dusseldorf, Germany, who says he is a relative of Patrick's. 
 
 Patrick Sondenheimer is the pilot believed to have been locked out of the cockpit by his co-pilot, Lubitz. 
 
 JUST WATCHED Germanwings pilot identified Replay More Videos ... MUST WATCH Germanwings pilot identified 01:38 
 
 CNN spoke to Reiner Sondenheimer at his Dusseldorf apartment. Also at the apartment was a woman who did not provide her name but said she was Patrick Sodenheimer's relative. That woman also said that Patrick Sondenheimer was on the doomed flight. 
 
 Reiner Sondenheimer declined to say anything else, other than the family wanted time to grieve. 
 
 The pilot has not been named by German authorities. 
 
 Another Germanwings pilot who once flew with Lubitz, Frank Woiton, told WDR, a local broadcaster belonging to CNN's German affiliate ARD, that his impression of Lubitz was that he was "friendly" and that there was "nothing suspicious." 
 
 Woiton also said Lubitz "was a good pilot and had a good command of the plane." 
 
 Woiton's first job after he found out about the crash was the route Dusseldorf-Barcelona-Dusseldorf -- the same route as had been taken by Germanwings Flight 9525 a day earlier. 
 
 He was praised in German media for the emotional announcement he made to passengers before takeoff, in which he said the crew, like everyone else on the plane, wanted to get home safely to their families. 
 
 Perilous recovery operation 
 
 At the scene of the crash, two helicopters were being deployed above the mountainside by recovery crews Saturday. The weather has improved after high winds Friday made their complex task even more treacherous 
 
 Lt. Col. Xavier Vialenc, a spokesman for the Gendarmerie, told CNN there were about 40 officers at the crash site Saturday. 
 
 Once at the crash site, recovery workers spend all day working there, he said. Back in Seyne-les-Alpes at the end of the day, they can see a psychologist if they choose and have a debriefing session with all the workers. 
 
 Vialenc said the operations were going well so far and that the progress made was meeting their expectations. 
 
 Yves Naffrechoux, captain of rescue operations at Seyne-les-Alpes, told CNN on Friday that rescuers have found bodies at the rugged crash site, but few of them are intact. 
 
 JUST WATCHED Investigators: Recovery effort going 'bit by bit' Replay More Videos ... MUST WATCH Investigators: Recovery effort going 'bit by bit' 02:10 
 
 It could be weeks before all the bodies are recovered, identified and released to the families, authorities said. 
 
 The mountainous terrain where the Germanwings jet went down is difficult to access. 
 
 Airline: Lubitz passed initial tests 
 
 What could have prompted Lubitz to deliberately destroy the aircraft, killing everyone on board, remains the focus of investigators in Germany. 
 
 JUST WATCHED Lufthansa CEO: Speechless that co-pilot crashed plane Replay More Videos ... MUST WATCH Lufthansa CEO: Speechless that co-pilot crashed plane 01:08 
 
 He had passed medical and psychological testing when he was hired in 2013, said Carsten Spohr , CEO of Lufthansa, which owns Germanwings. 
 
 Spohr also told reporters that Lubitz had "interrupted" his pilot training, which he began in 2008. That break lasted several months, he said, but added that such an interruption isn't uncommon. Spohr didn't give a reason for the break. 
 
 While the ailment Lubitz had sought treatment for hasn't been revealed, that he was declared unfit for work is an important detail, aviation analysts say. Pilots are required to maintain their fitness to fly and must tell their airline if they're found unfit, CNN aviation analyst David Soucie said. 
 
 Although authorities have recovered the cockpit voice recorder, the flight data recorder remains missing. It could shed crucial details about what happened inside the cockpit, authorities say. 
 
 Banging and screaming 
 
 Lubitz was the co-pilot on Tuesday's flight between Barcelona, Spain, and Dusseldorf when he apparently locked the captain out of the cockpit, then activated a control causing the plane to descend toward rugged terrain. 
 
 Germanwings said the plane dropped for about eight minutes from its cruising altitude of 38,000 feet before crashing. 
 
 The only sounds , authorities said, were those of pounding on the cockpit door, Lubitz's steady breathing and, eventually, screaming passengers. 
 
 Lubitz and 149 other people on board the plane died in an instant, authorities say. Most were from Germany and Spain.
– There's been a wave of new developments this morning regarding Germanwings co-pilot Andreas Lubitz and the downed flight. German prosecutors say that it appears Lubitz researched both suicide methods and cockpit door security during the period from March 16 to March 23, reports the AP; the crash occurred on March 24. The announcement stems from prosecutors' discovery of an iPad in Lubitz's apartment and a review of its browser history, report the New York Times, which has this statement: "During this time the user was searching for medical treatments, as well as informing himself about ways and possibilities of killing himself. On at least one day the person concerned also spent several minutes looking up search terms about cockpit doors and their safety measures." The revelations come along with the news that the second black-box recorder has been found, reports the AP. Meanwhile, CNN talks to a law enforcement source who says Lubitz went doctor-shopping in advance of the crash: The source says Lubitz saw five to six doctors—including a sleep specialist—and frames that as reflective of his fear that his medical woes would end his career and his desire to find a doctor who could help.