ORLANDO -- A man who says he was Orlando shooter Omar Mateen's gay lover is speaking out following the attack on Pulse nightclub that left 49 people dead, and dozens more injured. 
 
 In an interview with Univision anchor Maria Elena Salinas, the man -- who was called "Miguel" to protect his identity -- said he first met Mateen on the gay dating app Grindr. 
 
 Report: Man claims to have been Omar Mateen's lover 
 
 Univision reported the FBI told the network that investigators have spoken with this man, but a law enforcement official would neither confirm nor deny this to CBS News. 
 
 The official told CBS News senior investigative producer Pat Milton that Mateen was a frequent user of online dating sites seeking relationships with both men and women. 
 
 Men and women have come forward to the FBI claiming to have had a relationship with Mateen, according to the law enforcement official, and all of those claims are being investigated. 
 
 Man who is being called "Miguel" speaks in an interview with Univision about his alleged relationship with Orlando shooter Omar Mateen. His appearance was altered to protect his identity. Univision 
 
 Miguel said in an interview with Univision that Mateen, who was killed by police during the rampage on the Pulse nightclub early on June 12, was gay. He described his relationship with Mateen as "friends with benefits." 
 
 He said the sexual relationship lasted about two months, and they met at a hotel in Orlando between 15 and 20 times. 
 
 Miguel told Univison that he believes Mateen intentionally targeted Latinos in retribution for feeling rejected by Puerto Ricans. 
 
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 "I believe this is not terrorism," Miguel said, despite investigators saying Mateen called 911 and posted to Facebook to pledge allegiance to ISIS during the rampage. 
 
 Rather, Miguel claimed Mateen was acting on revenge after being with a Puerto Rican man whom he later learned was HIV positive. 
 
 "He hate gay Puerto Ricans for all the stuff he did to him," Miguel said. "I believe this crazy horrible thing he did was for revenge." 
 
 Miguel said that Mateen's wife knew he was gay, and that his father forced him into an arranged marriage. 
 
 Miguel added that he and Mateen also talked about religion. 
 
 "He said Muslim religion is beautiful, beautiful religion, where everything is about love," he said. "Everybody is welcome. Gay, trans, bisexual... everybody." 
 
 Miguel said that Mateen never appeared to be violent. 
 
 "He was looking for love," Miguel said. "He was looking to be embraced." 
 
 Investigators have said Mateen "cased" the Pulse nightclub prior to the night of the massacre. There has also been speculation about the gunman's sexuality. 
 
 A U.S. official with knowledge of the situation previously told CBS News that club-goers have told investigators that Mateen had been at Pulse numerous times previously. Additionally, other media outlets have heard several stories of Mateen popping up and conversing with men on gay dating apps. 
 
 Jim Van Horn, 71, said Mateen was a "regular" at the popular Pulse nightclub. 
 
 Van Horn, a retired pharmacist, said he met Mateen once, and the younger man talked about his ex-wife. But Van Horn said his friends soon "told me they didn't want me talking to him, because they thought he was a strange person." 
 
 The Orlando Sentinel and other news organizations quoted other regulars from Pulse who said they had seen Mateen there a number of times, and many said he was at best strange, at worst a little scary. 
 
 "Sometimes he would go over in the corner and sit and drink by himself, and other times he would get so drunk he was loud and belligerent," said Ty Smith, who remembered seeing Mateen inside at least a dozen times. 
 
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 Asked about his son's sexual orientation last week, Seddique Mir Mateen said he did not believe his son was gay. 
 
 "To me, that is wrong," Mateen's father told CBS News correspondent David Begnaud. 
 
 The elder Mateen said he learned of the speculation from news reports, but as far as he was concerned, "I didn't see any of it and I don't believe that was the case." 
 
 While it is still possible Mateen was just very closely surveying his chosen target for terror, former senior FBI profiler Mary Ellen O'Toole told CBS News that doesn't seem likely. 
 
 "This to me suggests somebody that may have had sexual identity issues and may have actually been struggling with the idea that he himself was gay and that would add a different motive and a different perspective on the case," O'Toole said. ||||| Breaking News Emails Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings. 
 
 / Updated By Pete Williams and Ayman Mohyeldin 
 
 Gunman Omar Mateen made his final stand at an Orlando nightclub, but why did he buy plane tickets to the West Coast — on a flight two days after the shooting? 
 
 A federal official confirmed to NBC News Tuesday that Mateen made the purchase for his family to travel to Northern California to visit his ailing mother-in-law. Wife Noor Zahi Salman's mother recently had an operation and was not getting better, and the family was planning on spending an extended period of time with her. 
 
 Related: Friend Who Told FBI About Orlando Shooter Omar Mateen Saw a 'Red Flag' 
 
 The tickets were purchased two days before the June 12 attack to travel to San Francisco on July 14 for two weeks. It's unclear, however, why Mateen would have bought the tickets if he was planning the shooting, only to die in it. 
 
 Mateen, who lived two hours south of the club in Port St. Lucie, was armed with a semiautomatic rifle and 9mm semiautomatic pistol when he slaughtered 49 people and injured 53 others in the worst mass shooting in modern U.S. history, police said. 
 
 Federal law enforcement officials said Mateen, 29, arrived at Pulse around midnight — but he left and then came back to the nightclub about two hours later to gun down his victims. 
 
 Investigators are trying to determine what he was doing for that two-hour period. 
 
 In addition, after combing through his electronic devices and doing interviews, they have not found anything to indicate that he was ever at Pulse in the days, weeks or months before the day of the shooting. 
 
 Related: DOJ Giving $1 Million in Federal Funds to Orlando First Responders 
 
 Right before Mateen had left the night of the attack, Salman became suspicious of her husband and pleaded with him not to do anything, a source told NBC News, although she did not call authorities. 
 
 A source close to the family said Mateen sent his wife a text message during the rampage, asking her, "Do you see what's happening?" After swapping texts, she tried to call him. Later, federal agents arrived at her door. 
 
 Salman, who has not been charged for failing to report her husband to law enforcement, continues to cooperate with investigators, a source said. ||||| (CNN) The Orlando shooter and his wife exchanged text messages during the Pulse nightclub rampage, a law enforcement official briefed on the investigation told CNN. 
 
 Around 4 a.m. on June 12, about two hours after he started the attack and while holed up in a bathroom, Omar Mateen texted his wife, Noor Salman, asking if she'd seen the news, the official said. 
 
 At one point, she responded with a text saying that she loved him. Salman also tried calling her husband several times during the standoff, a second law enforcement official said. 
 
 The timing of her calls came after reports of the attack had emerged, and apparently after she realized her husband might be responsible. He didn't answer, the official said. 
 
 It's not clear if Salman made any attempt to report her husband during that time. 
 
 Salman is coming under increasing scrutiny as police investigate the killing of 49 people and wounding of at least 50 at the gay nightclub in Orlando. Authorities say Mateen carried out the killing with a Sig Sauer MCX semi-automatic assault-style rifle and a pistol. 
 
 Salman apparently gave conflicting accounts about what she knew of Mateen's intentions in the hours before the attack. authorities said. She also told investigators that in the weeks before the attack, Mateen spent thousands of dollars, including for the guns used in the attack. 
 
 Mateen and Salman married in 2011. They have a 3-year-old son and lived in Fort Pierce, about two hours from the massacre. 
 
 A U.S. attorney plans to bring evidence before a federal grand jury to determine whether charges will be filed, two law enforcement officials said. 
 
 Facebook postings 
 
 Mateen also vented on Facebook before and during the massacre. 
 
 "America and Russia stop bombing the Islamic state," the gunman wrote, according to the chairman of the Senate Committee on Homeland Security and Governmental Affairs. 
 
 "You kill innocent women and children by doing us airstrikes ... now taste the Islamic state vengeance." 
 
 Then, in his final post, an ominous warning: ''In the next few days you will see attacks from the Islamic state in the usa." 
 
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 The messages were described in a letter from committee Chairman Ron Johnson to Mark Zuckerberg, asking the Facebook CEO to provide "all Facebook data on Mr. Mateen's activities on his account and any affiliated Facebook accounts." 
 
 It's not the only time Mateen invoked ISIS during his rampage early Sunday. In the middle of killing 49 people, Mateen also called 911 to pledge allegiance to the terror group and CNN affiliate News 13 to say, "I did it for ISIS. I did it for the Islamic State." 
 
 And an analysis of Mateen's electronic devices showed searches for jihadist propaganda, including videos of ISIS beheadings, an official said. 
 
 Reported gun store visit 
 
 The owner of a Florida gun store said Thursday that employees contacted the FBI four or five weeks ago because they became suspicious when Mateen tried to purchase body armor and a large amount of ammunition. 
 
 Robert Abell of Lotus Gunworks in Jensen Beach said a man asked for soft and then hardened body armor but was told the store didn't carry that merchandise. 
 
 During his visit, the man spoke on the phone to somebody in a foreign language and asked to buy 1,000 rounds of ammunition -- a request the store turned down, Abell said. 
 
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 The store called the FBI with the suspicions, Abell said, but didn't know the man's name. 
 
 The FBI investigated another incident reported by the gun store owner that coincided with Mateen's possible visit, three law enforcement officials told CNN. 
 
 Agents originally looked into a call from the store about a group of suspicious foreign men appearing to be of Middle Eastern descent, who were buying police gear. 
 
 The FBI tracked down the men, who were visiting government security officers from a Middle Eastern country. The purchase was not deemed suspicious, the sources said. 
 
 When the FBI closed the matter with the store, an employee mentioned another unidentified suspicious man who days before had tried to buy Level 3 body armor. 
 
 There was no name or any purchase record to review. The FBI asked the person at the store if there was surveillance footage or a car description or license plate. There wasn't. 
 
 After the shooting, store employees realized the man was Mateen, Abell said. 
 
 The FBI had no official comment on the matter when reached Thursday night. 
 
 Spokesmen for the Florida Department of Law Enforcement and the Martin County Sheriff's Office said the agencies don't have any records of receiving calls from Lotus Gunworks. 
 
 ISIS, or personal conflict? 
 
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 Despite mounting pledges of allegiance to ISIS, some say they believe Mateen was actually fueled by struggles with his sexuality -- and may have latched on to ISIS as a vehicle for his anger. 
 
 Several regulars at the gay nightclub said the gunman visited frequently over the past few years. Cord Cedeno said Mateen saw him at Pulse and messaged him on Grindr, a gay dating app. 
 
 Cedeno said he wasn't interested in Mateen, but his friend was. 
 
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 "One of my friends ... has been speaking with him since 2007, on and off," on another gay dating app, Cedeno said. 
 
 "(Mateen) sent him a picture of his private part, and my friend actually was attracted to him. He almost went and hooked up with him." 
 
 FBI agents are interviewing people who claim they met the gunman on gay dating apps, a law enforcement official said. Those claims "certainly change the perspective," the source said. 
 
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 CNN military analyst Lt. Gen. Mark Hertling said the gunman's complex background makes the investigation challenging. 
 
 "I'm not a psychiatrist, but the struggle with his humanity, his sexuality, combined with the potential for putting the onus on an organization that's asking people to do this -- asking extremists to do these kinds of things -- is an interesting dynamic," he said. 
 
 "And that's the thing that makes this case so extremely difficult." 
 
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 The gunman's ex-wife, Sitora Yusufiy, said she was not sure about his sexuality. 
 
 "It doesn't surprise me that he might be gay," she said. "And it doesn't surprise me that he was leading two totally different lives and was in such deep conflict within himself." 
 
 But the gunman's father, Seddique Mateen, has said he didn't think his son was gay. He emphasized that Mateen had a wife and child. 
 
 Victim's video 
 
 Throughout Orlando, survivors mourned the dead and recalled their experience. 
 
 Miguel Leiva shot cell phone video while huddled inside a bathroom with about 16 other people, he told CNN's Anderson Cooper on Thursday night. 
 
 The video showed people passing a cup of water around. One man was choking on his own blood, Leiva said. They whispered because they feared the gunman, who twice came back and fired his weapon, would return. 
 
 "I just remember you can smell the blood, there was so much blood," Leiva said. "All my clothes was full of blood. We were sitting down and there was a huge puddle of blood." 
 
 Only five or six people made it out alive, he said. Leiva was shot in the foot and leg. 
 
 "So many innocent people just there to have a good time."
– The mystery that was Omar Mateen is still unraveling more than 10 days after the Orlando nightclub massacre. In a Univision interview that aired Tuesday night, a man who gave his name as Miguel came forward claiming to be Mateen's lover, CBS News reports. He said he met Mateen on the gay dating app Grindr and that they met in an Orlando hotel 15 or 20 times over the course of a two-month relationship. He said Mateen was in an arranged marriage and his wife knew he was gay. Miguel said Mateen carried out the shooting rampage after discovering that a Puerto Rican man he dated was HIV-positive. "He [hates] gay Puerto Ricans for all the stuff he did to him," Miguel told interviewer Maria Elena Salinas. "I believe this crazy horrible thing he did was for revenge." A law enforcement official declined to confirm or deny to CBS that the FBI had spoken to Miguel, but he said Mateen was a frequent user of dating sites and authorities have interviewed both men and women who say they had relationships with him. In another twist, a federal official tells NBC News that two days before the June 12 attack, Mateen bought plane tickets for his family, apparently including himself, to visit California, where his ailing mother-in-law lives, on June 14. Investigators say that on the night of the attack, Mateen first visited the Pulse nightclub around midnight and left soon afterward. They are trying to figure out what he was doing between then and 2am, when he returned to carry out the massacre. (Mateen spent $9,000 on jewelry days before the attack.)