Two firearms, including a “long rifle,” were found at Club Q after the Saturday night shooting, said Police Chief Adrian Vasquez.
Investigators were still determining a motive, and the attack was being investigated to see if it should be prosecuted as a hate crime, said El Paso County District Attorney Michael Allen.
Charges against the suspect “will likely include first-degree murder,” he said.
Police identified the gunman as Anderson Lee Aldrich, who was in custody and being treated for injuries.
A man with the same name and age was arrested in 2021 after his mother reported he threatened her with “a homemade bomb, multiple weapons and ammunition,” according to authorities.
Police did not confirm whether it was the same person, saying they were investigating whether the suspect had been arrested before.
Authorities were called to the Club Q at 11:57 pm Saturday with a report of a shooting, and the first officer arrived at midnight.
“At least two heroic people” confronted the gunman and stopped the shooting, Vasquez said, adding: “We owe them a great debt of thanks.”
Of the 18 people injured, some were in critical condition and at least two had been treated and released, officials said, adding that some were hurt trying to flee.
The shooting brought back memories of the 2016 massacre at the Pulse gay nightclub in Orlando, Florida, that killed 49 people.
And it occurred in a state that has experienced several notorious mass killings, including at Columbine High School in 1999, a movie theatre in suburban Denver in 2012 and at a Boulder supermarket last year.
It was the sixth mass killing this month and came in a year when the nation was shaken by the deaths of 21 in a school shooting in Uvalde, Texas.
Club Q is a gay and lesbian nightclub that features a “Drag Diva Drag Show” on Saturdays, according to its website.
In addition to the drag show, Club Q’s Facebook page said planned entertainment included a “punk and alternative show” preceding a birthday dance party, with a Sunday “all ages brunch.”
Drag events have become a focus of anti-LGBTQ rhetoric and protests in recent months as opponents, including politicians, have proposed banning children from such events and falsely claim they’re being used to “groom” children.
Attorney General Merrick Garland was briefed on the shooting, Justice Department spokesman Anthony Coley said.
The FBI said it was assisting but said the police department was leading the investigation.
President Joe Biden said that while the motive for the shootings was not yet clear, “we know that the LGBTQI+ community has been subjected to horrific hate violence in recent years.”
“Places that are supposed to be safe spaces of acceptance and celebration should never be turned into places of terror and violence. Yet it happens far too often,” he said.
“We must drive out the inequities that contribute to violence against LGBTQI+ people. We cannot and must not tolerate hate.”
Colorado Gov. Jared Polis, who became the first openly gay man in the United States to be elected governor in 2018, called the shooting “sickening.”
“My heart breaks for the family and friends of those lost, injured, and traumatised in this horrific shooting. I have spoken with Mayor (John) Suthers and clarified that every state resource is available to local law enforcement in Colorado Springs,” Polis said.
“Colorado stands with our LGTBQ community and everyone impacted by this tragedy as we mourn.”
A makeshift memorial sprang up Sunday near the club, with flowers, a stuffed animal and candles in front of cardboard sign with the message, “Love over hate” next to a rainbow- colored heart.
Ryan Johnson, who lives near Club Q and was there last month, said it was one of only two night spots for the LGBTQ community in conservative-leaning Colorado Springs.
“It’s kind of the go-to for pride,” the 26-year-old said, describing it as a medium-sized club.
When he got home early Sunday, he saw police cars crowding the streets.
“It just feels crazy, you hear about it and you don’t think it’ll happen and then it happens,” said Johnson.
“You come to Colorado and feel safer than other parts of the country and then this happens.”
Although a motive wasn’t yet clear, nor were the gender identities of the victims, the incident came as anti-gay rhetoric has intensified by extremists. In a statement, Club Q termed the shooting a hate attack.
“Club Q is devastated by the senseless attack on our community,” the club posted on its Facebook page. It said its prayers were with victims and families, adding: “We thank the quick reactions of heroic customers that subdued the gunman and ended this hate attack.”
The CEO of a national LGBTQ-rights organisation, Kevin Jennings of Lambda Legal, reacted with a plea for tighter restrictions on guns.
“America’s toxic mix of bigotry and absurdly easy access to firearms means that such events are all too common and LGBTQ+ people, BIPOC communities, the Jewish community and other vulnerable populations pay the price again and again for our political leadership’s failure to act,” he said in a statement.
“We must stand together to demand meaningful action before yet another tragedy strikes our nation.”
The shooting came during Transgender Awareness Week and hours before Sunday’s International Transgender Day of Remembrance, when events around the world are held to mourn and remember transgender people lost to violence.
The Colorado Springs shooting was sure to bring special resonance to those events.
Colorado Springs is a city of about 480,000 located about 112 kilometers south of Denver that is home to the U.S. Air Force Academy, as well as Focus on the Family, a prominent evangelical Christian ministry.
In November 2015, three people were killed and eight wounded at a Planned Parenthood clinic in the city when authorities say a gunman targeted the clinic because it performed abortions.
In June, 31 members of the neo-Nazi group Patriot Front were arrested in Coeur d’Alene, Idaho, and charged with conspiracy to riot at a Pride event. Experts warned that extremist groups could see anti-gay rhetoric as a call to action.
The previous month, a fundamentalist Idaho pastor told his small Boise congregation that gay, lesbian and transgender people should be executed by the government, which lined up with similar sermons from a Texas fundamentalist pastor.
There have been 523 mass killings since 2006 resulting in 2,727 deaths as of Nov. 19, according to The Associated Press/USA Today database on mass killings in the US.