COLORADO SPRINGS — A man shrouded in body armor and wielding an AR-15 style rifle attacked an L.G.B.T.Q. nightclub in Colorado Springs on Saturday night, in a rampage that killed at least five people and injured at least 25 others.
At least one person inside the nightclub, Club Q, tackled and subdued the gunman, the authorities said, helping to prevent further bloodshed. Mayor John Suthers of Colorado Springs said that a man had grabbed a handgun from the gunman and then hit him with it, subduing him. When the police burst into the club, the man was still on top of gunman, pinning him down, Mr. Suthers said.
The owners of the club, who had looked at surveillance tape, lauded the actions of two patrons whom they said they did not know but who, together, had overpowered the gunman and held him on the floor until police arrived.
“One customer took down the gunman and was assisted by another,” said Matthew Haynes, one of the club owners. Referring to the first person who acted, Mr. Haynes added, “He saved dozens and dozens of lives. Stopped the man cold. Everyone else was running away, and he ran toward him.”
Police officials identified the gunman as Anderson Lee Aldrich, 22. He was injured and treated in a hospital. The police recovered two guns at the club, said Adrian Vasquez, chief of the Colorado Springs Police Department. The authorities said they were still working to determine who owned the long rifle used in the shooting, as well as other weapons found at the scene.
Mr. Vasquez said the suspect had not spoken with investigators and did not appear to have said anything at the crime scene. He said the shooting had lasted barely a minute.
The local district attorney, Michael J. Allen, said in a statement that his office expected that “the case will officially transfer to my office” for a charging decision in the coming days. He said the shooting appeared to have been carried out by a single person. The F.B.I. was also involved in the investigation.
The exact number of injured victims was uncertain. Some people had driven themselves to seek treatment, police officials said, and not all injuries were from gunshot wounds. Some may have suffered injuries while fleeing. At least two remained in critical condition on Sunday morning, doctors from two hospitals said.
The shooting erupted minutes before midnight, as revelers enjoyed a night out in a club considered a safe haven for the L.G.B.T.Q. community. It was painfully reminiscent of the 2016 massacre at Pulse, a gay nightclub in Orlando, Fla., where a gunman killed 49 people and wounded 53 others after proclaiming allegiance to the Islamic State terrorist group.
Joshua Thurman, who had gone to Club Q for an early birthday celebration, thought the first gunshots were part of the music. He stayed on the dance floor, but when he heard more shots and saw a flash from the muzzle of a gun, he ran to a dressing room at the rear of the club. He stayed there with a drag performer and another patron and described hearing the “pow! pow!” of gunshots.
“When we came out of the dressing room, we saw bodies,” he recalled on Sunday morning, choking back a sob. “There was broken glass, blood — I lost friends!”
Mr. Thurman, 34, spoke to reporters outside the club, where he had gone to retrieve his car from the parking lot. He said he had worked at the club as a go-go dancer and that a bartender whom he had come to know over the years was among those killed.
Mr. Thurman said Club Q was a “safe place” for its patrons: “This is a place we love, a place of peace, a place to be ourselves.”
The motive behind the attack at Club Q was still unknown. Mayor Suthers said the shooting “has all the appearances of being a hate crime,” but he said that investigators were still combing through the gunman’s social media history and doing interviews to determine a motive.
President Biden denounced the apparent targeting of the L.G.B.T.Q. community.
“Places that are supposed to be safe spaces of acceptance and celebration should never be turned into places of terror and violence,” he said in a statement. “We cannot and must not tolerate hate.”
Mr. Biden renewed his call for a federal assault weapons ban, though there is not enough support in Congress to enact one. “When will we decide we’ve had enough?” he asked. “We must address the public health epidemic of gun violence in all of its forms.”
A man with the same name and age as the club shooting suspect was arrested in June 2021 after the man’s mother had called the police and said that she was not with her son and did not know where he was, but that he had threatened to hurt her with a bomb, ammunition and other weapons. Police negotiators persuaded him to walk out of a house and surrender — but not before the police had evacuated residents from about 10 nearby houses in a suburban neighborhood just outside of Colorado Springs, because of the bomb threat.
The police have not said whether the shooting suspect and the man arrested in 2021 are one and the same.
The man was charged with several crimes after that arrest, including felony menacing and three kidnapping charges. It is unclear whom he was accused of kidnapping.
The police said in 2021 that they had not found any explosives. A spokesman for the local district attorney declined to say on Sunday how the charges were resolved.
The mother of the Anderson Aldrich involved in that case had been renting a spare room from Leslie Bowman, who said in an interview on Sunday that she had been away at the time.
“His mom had called me and said, ‘Don’t come home right now, there are some people looking for Andy,’” Ms. Bowman recalled, using the man’s nickname.
On Sunday, after the shooting, Ms. Bowman was left wondering why the man may have been at large and able to get hold of a rifle, if he had been accused of the bomb threat.
“Why is he not in jail, after that happening?” Ms. Bowman asked. “After that initial day, police never reached out to me for additional information. I’m a Second Amendment supporter, don’t get me wrong. But for him to be out there, and have access to weapons after that incident, I don’t understand it.”
Efforts to reach family members of the Mr. Aldrich arrested in the shooting on Sunday were unsuccessful.
Colorado Springs, a city of about 500,000 people south of Denver, is a Republican stronghold, and for decades it was a center for conservative Christian efforts to pass laws limiting the rights of gay people.
But the city, which has long had a small but vibrant L.G.B.T.Q. community, has become more diverse. It now hosts an annual Pride parade, and its fast population growth has diluted the influence of far-right conservatives.
Club Q stands on a major commercial boulevard, next to a Walgreens drugstore and a Subway sandwich shop. The club first opened in 2002, in the inconspicuous location behind a strip mall that the founder chose in part because, at the time, patrons needed an entrance where they could come and go without being seen, said Nic Grzecka, who co-owns the club with Mr. Haynes.
The owners said that when they reviewed surveillance video of the shooting, they saw the gunman pull up heavily armed and wearing a military-style flak jacket. Mr. Haynes said the gunman had entered the nightclub with “tremendous firepower” — a rifle and what appeared to be six magazines of ammunition — and began shooting.
Police officers arrived and took the gunman into custody within six minutes of receiving an emergency call about the shooting. Mr. Grzecka and Mr. Haynes got there a few minutes later. “It was chaos,” Mr. Haynes said.
Hours before the shooting, Club Q posted on Facebook about a “musical drag brunch” on Sunday morning to mark the Transgender Day of Remembrance, which honors the memory of those who lost their lives to anti-transgender violence.
After the 2016 mass shooting at Pulse, Mr. Haynes said he and Mr. Grzecka were “vigilant” about security at their club.
“We’ve worked with the Colorado Springs Police Department and the F.B.I. in response to various threats over the years,” he said. “But there had been no known recent threats toward Club Q.”
After the Pulse shooting, Mr. Grzecka said, the gay community in Colorado Springs had come together, “thinking we were taking a stance.”
He added, “We had this vigil, standing in our parking lot, never thinking this was going to happen in our community.”
Jack Healy reported from Colorado Springs, Mitch Smith from Chicago, Adam Goldman from Washington and Patricia Mazzei from Miami. Reporting was contributed by Noel Black, Nicholas Bogel-Burroughs, Charlie Brennan, Emma Bubola, Emily Cochrane, Jill Cowan, Eliza Fawcett, Eduardo Medina, Dave Philipps, Víctor Manuel Ramos, April Rubin, Ava Sasani, Mindy Sink, Luke Vander Ploeg, Daniel Victor and Cassandra Vinograd. Alain Delaquérière and Kirsten Noyes contributed research.