Authorities say a potential mass-casualty attack was stopped in Nevada after police arrested a suspect accused of planning a shooting on the Las Vegas Strip and discovered a large weapons cache that included more than 50 firearms, machine guns and grenade launchers.
Allison Howlett, 36, identified by police in the arrest report as transgender, was taken into custody on June 27 after Henderson officers received an urgent 911 call from Howlett’s spouse about a domestic dispute, a stolen SUV packed with weapons, and alleged threats involving “suicide by cop” and a mass shooting.
Investigators used vehicle-tracking technology to locate the stolen SUV inside a parking garage at Sunset Station casino, where officers surrounded it after finding Howlett inside with music playing loudly and allegedly ignoring repeated orders to get out.
Henderson police found the suspect’s vehicle in the Sunset Station parking garage before taking Howlett into custody. (KVVU)
Police said officers eventually persuaded Howlett to roll down a window by offering water, then removed the suspect from the SUV and used a Taser during the ensuing struggle.
“It should be noted that the suspect had been sitting on a handgun and had access to a fully automatic, silenced MP5-style machine gun in the back seat of the vehicle, further corroborating the reported threats of suicide by cop and having the means to carry out a mass shooting,” Henderson Police Chief Reggie Rader said during a news conference Tuesday.
🚨 Know something we should investigate?
📩 stepheny.price@fox.com
📸 IG: @fndstephprice
Authorities say detectives recovered 22 guns from the stolen vehicle, including handguns, rifles, a fully automatic firearm, suppressors, high-capacity magazines and hundreds of rounds of ammunition.
A subsequent search warrant executed at Howlett’s Henderson residence uncovered 30 additional guns, including automatic weapons, an M2 .50-caliber machine gun, two Colt AR-style rifles equipped with M203 grenade launchers, seven suppressors and thousands of rounds of ammunition, investigators said.
Authorities displayed dozens of guns seized during the investigation. (LVMPD)
As the investigation unfolded, Henderson police enlisted the Las Vegas Metropolitan Police Department’s Southern Nevada Counter Terrorism Center, the FBI Joint Terrorism Task Force and the FBI’s Las Vegas Field Office.
Assistant Sheriff Dori Koren said investigators uncovered evidence that Howlett allegedly made threats over an extended period of time.
Officers secured the area after locating the suspect at Sunset Station casino. (KVVU)
“Some of that information included the threat of wanting to become an active shooter or to conduct a mass attack here in Las Vegas,” Koren said.
READ MORE: Teen Shot Dead While Defending Young Boy From Bully, Police Say
Police also played audio during Tuesday’s news conference that investigators said was recorded in 2024 and captured Howlett allegedly threatening a future mass shooting.
“If the FBI doesn’t come … arrest me, there’s gonna be a … massacre. … One day … hundreds of people [are] going to lose their lives,” the person heard in the recording says.
“Obviously, for our community here in Las Vegas, after dealing with One October, those types of threats are taken very seriously,” Koren said, referencing the 2017 Route 91 Harvest festival shooting, which authorities have called the deadliest mass shooting in modern U.S. history.
Investigators said the alleged threats, coupled with the cache of weapons, prompted the immediate expansion of the investigation into a counterterrorism case.
Howlett now faces 35 criminal counts, including making threats related to an act of terrorism, assault with a deadly weapon constituting domestic violence, grand larceny of a vehicle, 22 counts of grand larceny of a firearm, multiple weapons offenses involving machine guns, suppressors and short-barreled rifles and resisting a public officer while armed with a firearm.
A judge set Allison Howlett’s bail at $500,000 after the arrest. (Clark County Justice Court)
A Clark County judge later set Howlett’s bail at $500,000.
The investigation began after Julie Howlett called 911 to report that her spouse had allegedly taken her vehicle and threatened a mass shooting.
If you or someone you know is having thoughts of suicide, please contact the National Suicide Prevention Lifeline at 1-800-273-TALK (8255).
Julie Howlett later told FOX5 Las Vegas that the 22 guns recovered from the stolen vehicle belonged to her and were part of her inventory as a gun dealer preparing to transport them out of state.
According to Julie Howlett, the confrontation began after she discovered Allison using her credit card without permission.
“That morning, I woke up to Allison spending money on my credit card,” Julie told FOX5. “She came in with a gun.”
Julie said she struggled to wrestle the firearm away after Allison allegedly pulled the trigger.
“She was going to kill me,” Julie said. “She took off. I ran outside. I had the gun still in my hand. I unloaded it.”
During Tuesday’s news conference, authorities confirmed investigators believe the firearms recovered from the vehicle belonged to the spouse. Officials said detectives are continuing to determine how the weapons were acquired, whether they were legally possessed and what role they allegedly played in the case.
Police have also alleged that Howlett made similar threats dating back to January 2024, including warning in a recorded statement that “there is going to be a mass shooting one day” if the FBI did not arrest the suspect.
Undersheriff Andrew Walsh said investigators are still working to determine a motive but warned the case highlights how rapidly violent threats can escalate.
“The time from thought to act — that window has closed,” Walsh said, explaining that suspected attackers today can move from making threats to carrying them out in a matter of days or even hours.
KSNV reported that, during a recorded interview with detectives after the arrest, Howlett denied planning a mass shooting or threatening anyone.
According to the outlet, Howlett said she and Julie Howlett had been married for four years and were both transitioning to female while taking estrogen and progesterone. Howlett also told investigators she took Julie’s vehicle simply to leave after an argument, acknowledged knowing firearms were inside because Julie had planned to transport them out of state, and claimed users on the online communications platform Discord had falsely accused her of making threats.
KSNV further reported that Howlett said all of her personally owned firearms had previously been legally transferred to Julie through an ATF-approved process.
Walsh urged anyone who hears credible threats of violence, particularly in domestic situations, to report them immediately, saying early intervention gives law enforcement the best chance to prevent tragedy.
As Southern Nevada prepares for Fourth of July celebrations, officials said law enforcement agencies remain on heightened alert and credited the coordinated response between Henderson police, Metro, the FBI and other regional partners with stopping what investigators believe could have become a mass casualty attack.
News Agency reached out to the Las Vegas Metropolitan Police Department and the FBI’s Las Vegas Field Office for additional comment. Both agencies said they had nothing further to add beyond officials’ remarks during Tuesday’s press conference.
