Carrying an AR-15 assault rifle and a handgun, Omar Mateen killed at least 49 people when he opened fire inside a gay nightclub in Orlando early Sunday morning. It has been called the deadliest mass shooting in U.S. history.
Here are the stories of some of the victims.
Edward Sotomayor, 34, was a caring, energetic man known for wearing a silly top hat on cruises, according to David Sotomayor, who said the two discovered they were cousins after meeting at Orlando's annual Gay Days festival around a decade ago.
David Sotomayor, who lives in Chicago, told The Associated Press Sunday that Edward worked for a company that held gay cruises and often traveled to promote the company's events.
"He was just always part of the fun," David Sotomayor said.
The two texted regularly and kept in touch, last seeing each other earlier this year at a filming of the television reality show "RuPaul's Drag Race," David Sotomayor said.
David Sotomayor is a drag queen who appeared on a season of the show using the name "Jade." He said Edward Sotomayor supported him and often sent him Facebook messages. They last exchanged messages late last week.
"You never think that's going to be the last time you speak to him," David Sotomayor said. "It's just heartbreaking to know it just can happen anytime."
Juan Ramon Guerrero, 22, told his cousin Robert Guerrero he was gay about two years ago, but he was worried about how the rest of his family would react. He did not tell them until just before the beginning of this year. And when he did?
"They were very accepting," said Guerrero, 19. "As long as he was happy, they were OK with it."
On Sunday morning, after learning that so many people had died at a gay nightclub, Pulse, that his cousin had gone to once in a while, Guerrero started to become concerned. Later in the day, his fears were realized when the family learned that Guerrero was identified as one of the victims.
Robert Guerrero said his cousin worked as a telemarketer and in recent months he started attending college at the University of Central Florida. Guerrero said his cousin didn't quite know what he wanted to study, but he was happy to be in school. And he was happy in a relationship with a person his relatives came to regard as a member of the family, Guerrero said.
"He was always this amazing person (and) he was like a big brother to me," he said of his cousin. "He was never the type to go out to parties, would rather stay home and care for his niece and nephew."
Stanley Almodovar III's mother had prepared a tomato-and-cheese dip for him to eat when he came home from his night out.
Instead, Rosalie Ramos was awakened by a call at 2 a.m. Sunday telling her something had happened.
Ramos told the Orlando Sentinel her son, a 23-year-old pharmacy technician, posted a Snapchat video of himself singing and laughing on his way to Pulse nightclub.
"I wish I had that (video) to remember him forever," she told the newspaper.
A friend, Hazel Ramirez, told the Washington Post she also saw a video from Almodovar on Snapchat and learned Sunday afternoon what had happened.
Ramirez described Almodovar as "kind, but sassy," and someone who was comfortable with his own sexual identity.
"He was so proud of who he was," she told the Post. "He would do his makeup better than anyone else. It was so easy to be myself with him.
Kimberly Morris, 37, moved to Orlando just months ago and had taken a job at Pulse nightclub as a bouncer, the Orlando Sentinel reported.
"She was so excited," ex-girlfriend Starr Shelton told the newspaper. "She'd just started working there and told me how she was thrilled to get more involved in the LGBT community there," Shelton said.
Friends described Morris as a kind, sweet person.
Narvell Benning met Morris when they were in college at Post University in Waterbury, Connecticut, where Benning said they both played basketball.
"I can't think of a time when I did not see a smile on her face," Benning told the Sentinel. "I'm so thankful of the good memories I have of her. This is just unreal."
Everyone loved Luis Vielma, a 22-year-old who worked at Universal Studios, friends said.
High school friend Eddi Anderson told the Tampa Bay Times that Vielma loved his job at the Wizarding World of Harry Potter and was known for his pleasant attitude and warm demeanor.
J.K. Rowling, the author of the Harry Potter books that spawned the movies and Orlando theme park, tweeted a picture of Vielma in a Hogwarts school tie, and said: "I can't stop crying."
Josh Boesch, who worked with Vielma at Universal, told the Orlando Sentinel: "He was always a friend you could call. He was always open and available."
Vielma "just wanted to make people smile," another co-worker, Olga Glomba, said.
Based on reporting by The Associated Press.