When a gunman opened fire on about 22,000 concertgoers in Las Vegas Sunday night, he killed 59 people and wounded 527 others in a state with a universal background check requirement that’s not enforced.

It’s still unclear how the shooter, Nevada resident Stephen Paddock, got his guns. Police reportedly discovered at least 23, including rifles and two modified to be automatic, in his room on the 32nd floor of the Mandalay Bay Resort and Casino, where he killed himself after the shooting. They found 19 other guns, potentially explosive chemicals, and thousands of rounds of ammo when they searched his car and home. But police didn’t say whether the weapons were purchased in Nevada.

Still, one of the deadliest mass shootings in U.S. history highlights the lax gun laws in Nevada, the state with the 14th-highest gun death rate and which doesn’t require a permit to purchase firearms — whether it’s handguns, rifles, or shotguns — according to the National Rifle Association.

Also in Nevada:

Guns aren’t required to be registered.

Open carrying is allowed without a permit, although it’s illegal to carry a concealed weapon without one.

There are no state-level regulations on automatic weapons.

There’s no waiting period required for gun sales.

There’s no magazine capacity limit.

There are no restrictions on selling modifications that could make a weapon automatic, including cranks that allow shooters to quickly pull the trigger multiple times.

In the last four years, Nevada has come close to requiring universal background checks at least twice. But because of government bureaucracy, what’s known as the “gun show loophole” remains: Nevada residents only need to go through background checks when they’re buying from licensed dealers. There’s no oversight when sales happen between private individuals, including online sales.

When Nevada does conduct background checks, it’s one of 12 states that run their own system for all guns, instead of relying solely on the FBI, according to the Bureau of Alcohol, Tobacco, Firearms, and Explosives. People with criminal records, a history of drug abuse, domestic abuse convictions, or mental illness can fail a background check. Public records, however, revealed no criminal record for Paddock. Two Nevada gun shops said Monday they sold to Paddock in the past year after passing background checks. But it’s unclear if Paddock used those guns in the attack.

In 2013, the Nevada Legislature passed a bill to require background checks on all gun sales, but Nevada Gov. Brian Sandoval vetoed it. He said the legislation would have imposed “unreasonable burdens and harsh penalties upon law-abiding Nevadans, while doing little to prevent criminals from unlawfully obtaining guns.”

“There are gun shows here in Nevada on a weekly basis,” former Democrat Sen. Justin Jones, the bill’s sponsor, told VICE News. “You can basically come to a gun show any particular weekend in Las Vegas and Reno and elsewhere.”

Most states don’t register gun shows, so it’s unclear how common they are from state to state, according to Everytown for Gun Safety, a nonprofit dedicated to reducing gun violence in the U.S.

Three years later in November 2016, residents narrowly approved a ballot initiative — 50.45 percent to 49.55 percent — to expand federal background checks to private gun sales. But the next month, the state attorney general’s office said the measure was “unenforceable” because the FBI wouldn’t conduct the new checks, which the federal agency considered the state’s responsibility. The Nevada attorney general’s office did not respond to a request for comment.

Don Turner, the head of the the Nevada Firearms Coalition (NFC), the NRA’s Nevada branch, told VICE News the state is “less restrictive” about gun laws and takes a “libertarian” approach to ownership.

“When someone has that kind of mentality, it doesn’t matter what kind of laws you have,” Turner said about the Las Vegas shooting. “NFC is deeply saddened by what happened. It’s not a reflection of the majority of gun owners in Nevada. NFC gun owners are dedicated to responsible and safe use of firearms. This is a tragedy.”

Proponents of stricter gun control are still fighting to implement the ballot initiative, according to Nevada Gun Safety Coalition co-chair John Saludes. They’re considering a lawsuit, working to elect a Democratic attorney general in the 2018 election, and considering how to amend the legislation.

“People should know that we are trying,” State Sen. Pat Spearman, a Democrat who represents Las Vegas, told VICE News. “We are trying with every fiber of our being. What this is, I believe, is a call to action for all of us to examine with our humanness. What can we do? What can we do to make this better?”

“We’ve all thought that whatever the last tragedy was would be the instigator to change, and every time we’ve been disappointed.”

The state did tighten a gun law this year which made it a felony for a person with domestic violence or stalking convictions to posses a gun. Spearman sponsored the legislation, which Turner’s group strongly opposed.

Jones, the Democratic senator who tried to pass gun control legislation in 2013, doesn’t expect Nevada legislators to take action following the shooting, especially since the legislature isn’t scheduled to meet again until February 2019.

“We’ve all thought that whatever the last tragedy was would be the instigator to change, and every time we’ve been disappointed,” Jones said.

Michael Hopper contributed to this report.