DENVER (AP) - Colorado became the 15th U.S. state on Friday to adopt a “red flag” gun law allowing firearms to be taken from people who pose a danger, securing a deeply emotional victory for an Aurora shooting survivor.

Democratic Gov. Jared Polis signed the bill, a top priority of his first term. It marked a painfully personal victory for first-term Democratic Rep. Tom Sullivan, whose son, Alex, was gunned down in the 2012 Aurora theater massacre that killed 12 people and wounded 70 others.

“Three hundred and fifty one Fridays since Alex was murdered,” Sullivan began, wearing his son’s leather bomber jacket at the signing ceremony for the bill he sponsored.

“Being the parent of a murdered child, everything is stunted,” Sullivan said, prompting knowing, tearful nods from several other shooting survivors standing behind him. “I am elated, believe me. It just can’t come out because there is just too much work in front of us to get done.”

Alex Sullivan was celebrating his 27th birthday at the theater. Tom Sullivan, elected to the House in November, has devoted his life since Aurora to counseling survivors of other mass shootings around the country and campaigning for gun control.

Florida passed its own “extreme risk protection order” law after the 2018 Parkland school massacre. Others with versions of the law include California, Connecticut, Delaware, Illinois, Indiana, Maryland, Massachusetts, New Jersey, New York, Oregon, Rhode Island, Vermont and Washington, as well as Washington, D.C.

Colorado’s law allows family, household members or law enforcement to petition a court to have guns seized or surrendered. A subsequent court hearing could extend a gun seizure up to 364 days.

The law places the burden of proof on the gun owner to get the firearms back by showing that he or she no longer poses a risk. That condition - and the bill itself - drew the ire of gun rights activists. Minority Republicans in the Legislature unsuccessfully tried to shift the burden of proof to the petitioner.

“Colorado has endured more than our fair share of tragedies,” Polis said.

He added: “This law will not prevent every shooting, but it can be used in a targeted way to make sure that those who are suffering from a mental health crisis” get care.

The law is named after Douglas County Sheriff’s Deputy Zackari Parrish III, a 29-year old husband and father who was killed on New Year’s Eve 2017 by a man who had exhibited increasingly erratic behavior.

Parrish’s boss, Douglas County Sheriff Tony Spurlock, and Boulder County Sheriff Joe Pelle attended. Pelle’s son, a Douglas County sheriff’s deputy, was wounded in the shooting that killed Parrish.

Pelle said he was working with Spurlock and other law enforcement chiefs to develop protocols for executing protective orders safely.

Co-sponsor Alec Garnett, a Democrat and the House majority leader, noted that Colorado’s law stands out for providing legal representation for gun owners.

“We have come a long way in this state from Columbine,” Garnett said, referring to the upcoming 20th anniversary of the April 20, 1999, Columbine High School massacre.

Gun rights activists say about half of Colorado’s 64 counties - most in rural areas - passed resolutions opposing the bill, symbolically declaring themselves “Second Amendment sanctuaries.”

Opposition from rural sheriffs elicited a warning from Democratic Attorney General Phil Weiser, who has said those who won’t enforce the law should resign.

It’s Colorado’s most significant gun legislation since background checks and ammunition magazine limits were enacted in 2013, following the Aurora and Sandy Hook Elementary School shootings. Two Democratic lawmakers were recalled and another resigned for supporting those laws.