Never-before-seen video released Thursday shows a security guard admitting an unidentified man into the Isabella Stewart Gardner Museum the night before the infamous 1990 art heist, adding a stunning new clue to Boston’s most enduring mystery. 
 
 The video footage, taken by the museum’s surveillance cameras and recently examined by investigators, shows the night watchman open the museum’s side door and grant unauthorized access to the man at about 12:49 a.m. on March 17, 1990 — 24 hours before the museum was robbed by two men dressed as police officers who arrived at the same door. 
 
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 The man spent about three minutes in the reception area and appears to fumble through paperwork or a wallet before leaving. 
 
 Law enforcement officials are now questioning whether the suspicious actions constituted a dry run for the heist, and it refocuses the spotlight on Richard Abath, the rock musician moonlighting as a security guard who fell under the suspicion of authorities soon after the robbery. Authorities did not say Abath was the guard in the video, but three officials familiar with the investigation confirmed to the Globe that it is he. 
 
 Officials released the video to solicit the public’s help in identifying the second man, hoping to make some movement in the largest unsolved art theft in the world. 
 
 It was not immediately clear why the surveillance footage of the night before the robbery had not been made public before, and whether it was viewed by the FBI in the initial investigation. The robbers had seized surveillance footage from the night of the heist, though they did not take footage from the previous night. 
 
 Several law enforcement officials said the video appears to have been overlooked and mixed in with other evidence at the onset of the case. US Attorney Carmen M. Ortiz said that a team of investigators began reviewing the original evidence, and that one of them, Assistant US Attorney Robert Fisher, requested the video, which was in the custody of the FBI. Officials then decided to release it to the public in hopes it could lead to new information. 
 
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 “We have this big question mark as to who this individual is,” Ortiz said. “The hope is that someone will recognize the unauthorized visitor . . . and provide some fruitful leads that will help us figure out where the paintings are, lead to some information, to some people we haven’t thought of before.” 
 
 Abath, who is now in his late 40s and lives in Vermont, has denied any ties to the robbery plot, though he admitted to violating museum protocol at the time of the robbery by opening the door to the two men dressed as police officers claiming to be responding to a disturbance. Protocol required him to seek a supervisor’s approval before letting anyone into the museum after hours. 
 
 A Globe reporter who went to Abath’s house Thursday morning in Brattleboro was turned away by a woman who said he did not live there. Abath has admitted to bringing friends to the museum at least once several months before the robbery, but he never disclosed that he let someone in the night before the heist. He has said he opened the door only for security checks. 
 
 “What you see in the video does not comport with what we have been told in the past,” said Anthony Amore, the museum’s director of security, who has worked with the FBI and the US attorney’s office in a renewed push in recent years to solve the heist. 
 
 He said the video “is compelling in that perhaps the identity of this person . . . will shed new light on exactly what happened March 18 [1990], who else may be involved, and hopefully lead us to our paintings.” 
 
 Globe reporters discuss new video in Gardner museum heist 
 
 No one can be charged with the theft of the paintings because the statute of limitations has expired, but authorities could still seek charges against someone in possession of the stolen works. Ortiz has said she would consider granting immunity to anyone who may possess the paintings in exchange for their return. The museum has offered a $5 million reward for the return of the works. 
 
 Abath, who has recently worked as a teacher’s aide in Vermont, has long been under suspicion, in part because of his admission to violating museum protocol and because of the way the robbery was carried out. 
 
 Once Abath buzzed the men into the museum’s side entrance on Palace Road at 1:24 a.m. on March 18, 1990, the men subdued him, then waited for the second guard on duty and tied him up as well. They then spent 81 minutes in the museum, making off with 13 works of art, including three Rembrandts, a Vermeer, and a Manet. 
 
 Investigators have questioned why Abath’s footsteps were the only ones picked up by motion detectors in the first-floor gallery, where one of the stolen paintings was taken, just before the two robbers scoured the rest of the museum. 
 
 One of Abath’s most questionable disclosures was that he opened and closed the Palace Road door 20 minutes before the robbery, which prompted investigators to ask whether he was signaling the robbers. The action was also in violation of security protocol, though Abath maintained he routinely opened the door during his rounds. 
 
 He did open the door on March 17. The footage starts just before 1 a.m., and it shows a car moving in reverse on Palace Road, a one-way street, after the second guard on duty went on his rounds. An unidentified man approaches the museum from the direction of the car, and Abath seems to grant him access through the first door by hitting an intercom button. 
 
 The man does not enter the museum’s second door, but returns to the car and turns on its parking lights. 
 
 The footage then shows the man returning to the museum. Abath again buzzes the man in, but this time the man remains in the museum reception area for more than three minutes before returning to the car and leaving. 
 
 The footage also shows that the unidentified man parked the car at roughly the same spot where several young people who had emerged from a St. Patrick’s Day party the morning of the robbery reported seeing a red hatchback. One of the partygoers reported seeing two men dressed as police officers inside, roughly an hour before the robbery occurred. 
 
 The color, make, and model of the car in the new surveillance video could not be determined, though authorities said Thursday that it matches the general description of the vehicle seen the night of the robbery. 
 
 Lyle Grindle, who headed security for the museum at the time of the theft, said in an interview Thursday that he had been shown the security tape by federal investigators about a month ago, but that he was unable to identify the visitor who had been allowed into the museum. He said he told investigators that allowing such a visit was a violation of the museum’s strict security procedures, which prohibited any late-night entries, even by police or firefighters. 
 
 Grindle said it appeared to him that the tape had been recently unearthed by the federal officials, but he did not ask why it had not been viewed before by investigators. 
 
 “I believe all the prior tapes from the previous nights were taken by the FBI, and I never saw them again,” said Grindle, who stayed on as security director for years after the heist and oversaw an upgrade of the museum’s security system. 
 
 Grindle said he did not know if Abath had been questioned by the federal officials who interviewed him. 
 
 “Someone has to explain why the security protocol was broken two nights in a row now, and I think only Rick can answer that question now,” Grindle said. 
 
 It was not immediately clear if Abath has recently discussed his actions that night with authorities. 
 
 No one has ever been charged in connection with the theft of the paintings, and none of the works have been recovered, making it Boston’s last great mystery following the capture and conviction of notorious gangster and longtime fugitive James “Whitey” Bulger. The artworks are considered priceless on the black market. 
 
 In 2013 the FBI publicly disclosed for the first time that agents believe they know who took the art, and that the works had made their way through underground organized crime channels from Boston through Connecticut to Philadelphia, where they were last believed to be seen. 
 
 Amore called the new video troubling, but added, “It doesn’t knock us off course on the stuff we’ve been talking about.” He said the video “raises more questions than answers.” ||||| Former Gardner Museum night watchman Rick Abath is pictured at an undisclosed location in February 2013. 
 
 BRATTLEBORO — Richard Abath never made a secret of his part in the story of the historic Isabella Stewart Gardner Museum heist. He talked about it as he worked on an undergraduate degree at the Union Institute & University, and he made it the topic of his senior paper. 
 
 In class, he explained casually that he had been working as a guard when thieves duct-taped him and ransacked the storied museum’s art collection on March 18, 1990. 
 
 “He’s like, ‘I have nothing to hide. I don’t care really,’ ” said Dana Johnson, who said she took courses with Abath, describing him as a a low-key guy, a mellow classmate. 
 
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 Abath’s history with the 25-year-old case came flooding back Thursday, as federal authorities made available footage of a night watchman opening the museum’s side door to let in an unidentified man about 24 hours before the robbery. 
 
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 Though officials have not officially identified Abath as the guard in the footage, three people close to the investigation confirmed to the Globe that it is he. 
 
 It’s been known for years that Abath opened the door for two men dressed as police officers on the night the robbery took place, and was later found bound by duct tape after the paintings were stolen. He was interviewed by the FBI, but has denied involvement in the heist. 
 
 Abath moved to Vermont in 1999 and graduated from college in 2010, according to the Brattleboro Reformer. For those in this laid-back Connecticut River town who knew the curly-haired, bearded Abath, who is now in his late 40s, his backstory never came up. 
 
 A neighbor recalled him as a friendly man, whose wife’s lovely singing voice rang out onto the street from their apartment not far from downtown. 
 
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 “I rarely ever talk to him, but he’s never been anything but kind,” neighbor Paul Canon, 53, said on Thursday. 
 
 At an address listed for him at a house on Clark Street, a woman yelled at reporters that “no one by that name lives here” and to “get away from my front door.” The name Abath was on the mailbox. 
 
 In releasing the new video, officials are now questioning whether the footage depicts a dry run for the heist. 
 
 Two years ago, Abath told the Globe he had met with federal agents at a Brattleboro coffee shop a few years earlier, and again denied any involvement in the theft. 
 
 “I totally get it. I understand how suspicious it all is,” Abath told Globe correspondent and author Stephen Kurkjian in an article published in March 2013. “But I don’t understand why [investigators] think . . . I should know an alternative theory as to what happened or why it did happen.” 
 
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 Abath was a 23-year-old Berklee College of Music dropout and a member of a struggling rock band at the time of the heist, and he was moonlighting as a security guard. 
 
 ‘I know I wasn’t supposed to let strangers into the museum after hours, but no one told me what to do if the police showed up.’ Richard Abath 
 
 He has admitted that, at that time in his life, he regularly drank alcohol and smoked pot and also occasionally took LSD and cocaine. He said he sometimes showed up for his midnight shift at the Gardner drunk or stoned, but that on the night of the heist he was sober. 
 
 That night, the two men disguised as police officers allegedly handcuffed and duct-taped Abath and a fellow guard before robbing the museum of 13 pieces of prized art. 
 
 Yet investigators believe Abath’s partying lifestyle at the time could have led him to meet the kind of people who might carry out such a crime, and they’ve pointed out that studies show a vast majority of museum robberies have been inside jobs. 
 
 Abath also made other curious moves prior to the heist. He had just given two weeks’ notice to quit the security job, and on the night of the robbery, about 20 minutes before the thieves arrived, Abath quickly opened and shut the door just before he replaced another security guard at the security desk. 
 
 Abath told the Globe that was his way of double-checking that doors were locked. 
 
 “I don’t know what the others did, but I was trained to do it that way,” he told Kurkjian. 
 
 And he said he later allowed the men inside because they looked like officers. 
 
 “I know I wasn’t supposed to let strangers into the museum after hours, but no one told me what to do if the police showed up saying they were there to investigate a disturbance,” Abath said. “What was I supposed to do?” 
 
 Questions have also arisen about why Abath’s footsteps were the only ones picked up by motion detectors in a first-floor gallery where one of the paintings was stolen, even though the thieves tripped detectors in other areas. And the frame of one of the stolen paintings was found by police on the chair of Abath’s boss near the security desk. 
 
 “They wanted to know if I had taken the painting and stashed it somewhere,” Abath told the Globe two years ago. 
 
 “I told them, as I’ve said a hundred times before and since, I had absolutely nothing to do with the robbers or the robbery,” Abath told Kurkjian, who has written a book about the Gardner case titled “Master Thieves: The Boston Gangsters Who Pulled off the World’s Greatest Art Heist.” 
 
 According to those who knew Abath as he attended college, he was unequivocal about his innocence in the case. 
 
 Alex Knight, 46, another student who said he went to Union with Abath, said it seemed like his classmate had nothing to hide and was open to talking about it. 
 
 However, Abath could also hold forth on topics including historical obscurities and existentialist theory. Knight called Abath a “very nice guy, very intelligent, very well read.” 
 
 Knight remembers Abath describing what he called an honest mistake, where he accidentally let in men posing as police officers. 
 
 “I hope that he was not involved in this. I hope that he was telling the truth,” Knight said. “It would certainly cast him in a different light if in fact he was proven beyond a reasonable doubt that he was guilty. That would alter, in my mind, his overall character significantly.” 
 
 Matt Rocheleau of the Globe staff contributed to this article. Andy Rosen can be reached at andrew.rosen@globe.com . Sara DiNatale can be reached at sara.dinatale@globe.com . Monica Disare can be reached at monica.disare@globe.com. ||||| BOSTON—Twenty-five years after the notorious burglary of the Isabella Stewart Gardner Museum in Boston, law enforcement officials are seeking the public’s assistance in identifying an unauthorized visitor to the museum the night before the theft. That person entered the museum through the same door as the thieves in the middle of the night, 24 hours before the theft. 
 
 “Over many months we have engaged in an exhaustive re-examination of the original evidence in this case. Our aim has been to ensure that all avenues have been explored in the continuing quest to recover these artworks,” said United States Attorney Carmen Ortiz. “Today we are releasing video images from the night before the theft—images which have not previously been seen by the public—with the hope of identifying an unauthorized visitor to the museum. With the public’s help, we may be able to develop new information that could lead to the recovery of these invaluable works of art.” 
 
 The video footage released today, captured by Museum security cameras 24 hours before the Gardner heist, shows an automobile pull up next to a rear entrance of the Museum. The car matches the general description of a vehicle that was reported to have been parked outside the Museum moments prior to the theft on March 18, 1990. 
 
 The video also shows an unidentified man exiting the automobile and then being allowed inside the Museum, against Museum policy, by a security guard. That event occurred at 12:49 p.m. on March 17, 1990, almost exactly 24 hours before the thieves entered the museum through the same door. 
 
 While the images of both the vehicle and the unidentified man are low resolution, law enforcement officials hope that releasing the footage will assist with identifying the man or the vehicle in the video. 
 
 Anyone with information regarding the video should call the FBI at 617-742-5533 or the Isabella Gardner Museum at 617-278-5114. 
 
 Vincent Lisi, Special Agent in Charge of the FBI in Boston said, “This latest request for the public’s assistance illustrates the FBI’s continued commitment to the Gardner investigation. By releasing this video, we hope to generate meaningful leads and ultimately recover the stolen artwork.” 
 
 A $5 million reward has been offered by the Museum for information that leads directly to the recovery of all of the stolen items in good condition. The recovery of an individual object will result in a portion of the reward, based upon the object’s market value relative to the other stolen objects. 
 
 “We remain committed to one goal: the return of all 13 works to their rightful place, which is here at the Isabella Stewart Gardner Museum. To that end, we support the efforts that the United States Attorney and the Federal Bureau of Investigation are making to uncover any and all information related to the theft of our artwork. We believe that no stone should be left unturned,” said Anthony Amore, Director of Security at the Gardner Museum. 
 
 In the early morning hours of March 18, 1990, two white males dressed in Boston Police uniforms gained entrance to the Gardner Museum by advising the security guard at the watch desk that they were responding to a report of a disturbance within the compound. Against Museum policy, the guard allowed the thieves into the facility. Upon entry the two thieves subdued the on-duty security personnel, handcuffed them, and secured both guards in separate remote areas of the Museum’s basement. The suspects did not brandish weapons, nor were any weapons seen during the heist. No panic button was activated and no Boston Police notification was made during the robbery. The video surveillance film from the evening of the robbery was seized by the thieves prior to departure. They did not take the video footage from the night before. 
 
 The combined value of the 13 works of art stolen during the Gardner theft is at least $500 million, though they are considered priceless within the art community. The following objects were stolen during the burglary and have been missing for the past 25 years: 
 
 1) Vermeer’s "The Concert" 
 
 2) Rembrandt’s "A Lady and Gentleman in Black" 
 
 3) Rembrandt’s "The Storm on the Sea of Galilee" 
 
 4) Rembrandt’s "Self Portrait" 
 
 5) Govaert Flinck’s "Landscape with an Obelisk" 
 
 6) A Shang Dynasty Chinese Bronze Beaker from 1200-1100 BC 
 
 7) Degas' "La Sortie du Pelage" 
 
 8) Degas' "Cortege Aux Environs de Florence" 
 
 9) Degas' "Three Mounted Jockeys" 
 
 10) Degas' "Program for an Artistic Soiree" (charcoal on white paper) 
 
 11) Degas' "Program for an Artistic Soiree" (less finished charcoal on buff paper) 
 
 12) Manet’s "Chez Tortoni" 
 
 13) Napoleonic Eagle Finial 
 
 - More information on Gardner Museum theft ||||| BOSTON (AP) — Twenty-five years after the famed art heist at Boston's Isabella Stewart Gardner Museum, law enforcement officials released new surveillance video Thursday showing an unauthorized visitor entering the museum the night before the robbery. 
 
 FILE - In this March 11, 2010 file photo, the empty frame, center, from which thieves cut Rembrandt's "Storm on the Sea of Galilee" remains on display at the Isabella Stewart Gardner Museum in Boston.... (Associated Press) 
 
 FILE - This undated file photograph provided by the Isabella Stewart Gardner Museum shows the painting "Chez Tortoni," by Edouard Manet, one of more than a dozen works of art stolen in the early hours... (Associated Press) 
 
 FILE - In this March 21, 1990 file photo, a security guard stands outside the Dutch Room of the Isabella Stewart Gardner Museum in Boston, where robbers stole more than a dozen works of art by Rembrandt,... (Associated Press) 
 
 In this March 18, 1990 still image from surveillance video released by the U.S. Attorney's Office,Thursday, Aug. 6, 2015, an unauthorized visitor walks inside the rear entrance of the Isabella Stewart... (Associated Press) 
 
 Authorities hope the never-before seen video will spark leads to help recover the 13 pieces of stolen artwork, worth at least $500 million. 
 
 The low-resolution video shows a security guard appearing to hit an intercom button, then to grant access to a man who can be seen in the museum's reception area at about 12:49 a.m. on March 17, 1990, nearly exactly 24 hours before the heist. 
 
 The man is also seen getting out of a car matching the general description of one reported to be parked outside the museum minutes before the theft. He uses the same rear entrance as the thieves, according to the office of U.S. Attorney Carmen Ortiz, which released the video. 
 
 The stolen artwork includes Vermeer's "The Concert" and Rembrandt's "The Storm on the Sea of Galilee." 
 
 Ortiz's office did not immediately respond to questions about why the video footage — captured by museum security cameras — was not released earlier. 
 
 "Over many months we have engaged in an exhaustive re-examination of the original evidence in this case. Our aim has been to ensure that all avenues have been explored in the continuing quest to recover these artworks," Ortiz said in a prepared statement. 
 
 Ortiz said officials are hoping the public may be able to help authorities identify the unauthorized visitor or the car seen in the video. 
 
 "With the public's help, we may be able to develop new information that could lead to the recovery of these invaluable works of art," she said. 
 
 A $5 million reward has been offered by the museum for information that leads to the recovery of the stolen artwork in good condition. 
 
 "We remain committed to one goal: the return of all 13 works to their rightful place, which is here at the Isabella Stewart Gardner Museum," said Anthony Amore, Director of Security at the Gardner Museum. 
 
 Authorities have repeatedly said on March 18, 1990, two white men dressed in Boston police uniforms gained entrance to the museum by telling the security guard at the watch desk that they were responding to a report of a disturbance. 
 
 Against museum policy, the guard allowed the men into the museum. The thieves handcuffed the museum's two guards on duty and put them in separate areas of the museum's basement. 
 
 No weapons were seen during the robbery and no panic button was activated. The video surveillance footage from the night of the robbery was taken by the thieves. 
 
 No one has ever been charged in the heist. 
 
 ___ 
 
 Online: https://www.youtube.com/watch?v=qSw1BsJEBB4
– The FBI hopes new surveillance footage released today will aid in the recovery of 13 priceless artworks stolen 25 years ago and help put to rest one of Boston's greatest mysteries. In the early hours of March 18, 1990, two men dressed as cops were let into the Gardner Museum, where they tied up two security guards and absconded with the artwork and the museum's security footage, the Boston Globe reports. But the thieves, who have never been identified, may have missed one key thing. According to the FBI, surveillance footage from the day before the robbery shows a security guard letting a man into the museum—against protocol—through the same door later used in the robbery. The Globe reports it's unclear why this footage wasn't viewed by law enforcement earlier, but it could show a "dry run" of the heist. The newspaper identifies Richard Abath as the security guard in the footage, and the FBI is hoping the public can help identify the mystery man he lets in. Abath, a rock musician at the time who now lives in Vermont, has claimed he had no part in the robbery, but this new footage appears to contradict a number of his statements. No one has ever been charged with stealing the art—for which there is a $5 million reward—and no one ever will, as the statute of limitations has expired. Someone in possession of the paintings, however, could face charges. Their total value exceeds $500 million, reports AP.