It has emerged that the shooter behind the worst terror attack in the US since September 11th was a regular at the gay bar he attacked in Orlando.

29-year-old security guard Omar Mateen shot dead 49 people at an the Pulse nightclub early Sunday morning.

All of the victims have now been identified.

"He (Mateen) certainly had been into Pulse nightclub on a number of occasions, one witness said that they'd seen him at least 12 times", Simon Carswell, Washington correspondent for the Irish Times, told Newstalk Breakfast.

"They described him as getting really drunk on some visits there; they said he spoke about his father, he spoke about his wife and family".

"And also he had potential to be violent there".

"One couple who used to drink in the nightclub claim that he ended up pulling a knife on them at one point - and on another occasion he was escorted out of the nightclub, very drunk".

"So a whole new picture is emerging that may suggest a different motive", he added.

Footage as shooting began

Meanwhile footage has emerged from inside the nightclub as he was carrying out his deadly gun rampage.

The video was posted on Snapchat by 25-year-old Amanda Alvear, who was one of 49 people killed in the Orlando venue on Sunday.

It shows revellers drinking and dancing before the footage cuts to Ms Alvear whispering the word "shooting" - a burst of about nine shots is then heard.

A second burst of gunfire comes less than a second later - this time about eight bullets are audible.

A friend of Ms Alvear posted the footage online:

Remembering the victims

Among the other clubbers who died in the Florida massacre was a man who worked on the Harry Potter ride at Universal Studios.

Luis S Vielma (22) had posted a photo of himself with friends at Disney World just hours before the shooting, with the caption: "True friends who become family."

Harry Potter author JK Rowling said on Twitter that he had worked on the 'Wizarding World Of Harry Potter' attraction at the theme park, adding: "I can't stop crying."

One friend Will Randle wrote on Facebook: "You were one of the kindest people I have ever come to know."

"At Disaster (another ride Mr Vielma worked on), everyone's day would brighten up whenever you came in. I don't care if it was an early opening, or a late event. Working with you was extraordinary."

Edward Sotomayor (34) who was described by his cousin as a caring and energetic man known for wearing a comedy top hat on cruises.

Mr Sotomayor worked for a company that organised gay cruises and spent much of his work life travelling to promote their events.

David Sotomayor, who lives in Chicago, described his cousin as "just always part of the fun."

The two had discovered they were related after meeting at a festival in Orlando about 10 years ago and they had texted and kept in contact regularly since then.

Edward Sotomayor supported his cousin, a drag queen, during filming of reality TV show RuPaul's Drag Race earlier this year.

David said: "You never think that's going to be the last time you speak to him. It's just heartbreaking to know it just can happen anytime."

Stanley Almodovar III's mother, Rosalie Ramos, said she had prepared a snack for her son to eat as soon as he returned from his night out at the club.

Instead she was woken at around 2am with the news about his death.

Ms Ramos told the Orlando Sentinel that her son had posted a Snapchat video of himself singing and laughing on his way to the nightclub, adding: "I wish I had that (video) to remember him forever."

Mr Almodovar (23) had been a pharmacy technician and one of his friends, Hazel Ramirez, told the Washington Post that he was "so proud of who he was."

Describing him as "kind but sassy", she added: "He would do his make-up better than anyone else. It was so easy to be myself with him."

Luis Omar Ocasio-Capo was just 20 years old and, according to his Facebook page, he worked as a dancer. The Daily Beast quoted a former teacher describing him as "a ray of sunshine every day."

Juan Ramon Guerrero (22) had told his cousin Robert that he was gay about two years ago and had also confided that he was worried about his family's reaction.

He did not tell his family until late last year and, to his surprise, found that they were "very accepting", his cousin said.

Mr Guerrero worked as a telemarketer and had also started attending college at the University of Central Florida a few months before the shooting.

According to his cousin Robert, Mr Guerrero did not know what he wanted to study but was just happy to be in school.

He was also in a happy relationship with a person his relatives had come to regard as a member of the family, he added.

"He was always this amazing person (and) he was like a big brother to me. He was never the type to go out to parties, would rather stay home and care for his niece and nephew."

Also among the dead were:

• Kimberly Morris, 37, a bouncer at the club
• Eric Ivan Ortiz-Rivera, 36
• Peter O Gonzalez-Cruz, 22
• Eddie Jamoldroy Justice, 30
• Darryl Roman Burt II, 29
• Deonka Deidra Drayton, 32
• Alejandro Barrios Martinez, 21
• Anthony Luis Laureanodisla, 25
• Jean Carlos Mendez Perez, 35
• Franky Jimmy Dejesus Velazquez, 50
• Martin Benitez Torres, 33
• Luis Daniel Wilson-Leon, 37
• Mercedez Marisol Flores, 26
• Xavier Emmanuel Serrano Rosado, 35
• Gilberto Ramon Silva Menendez, 25
• Simon Adrian Carrillo Fernandez, 31
• Oscar A Aracena-Montero, 26

And the father of Omar Mateen has claimed the attack could have been prevented if the club had better security.