Henderson police arrested Allison Howlett, 36, on June 27 after a 911 call from the suspect's spouse triggered a counterterrorism investigation that authorities say may have prevented a mass casualty attack on the Las Vegas Strip. Officers recovered more than 50 firearms across two locations, including machine guns, grenade launchers and thousands of rounds of ammunition.
The Arrest and What Officers Found
The case began when Julie Howlett called 911 to report a domestic dispute, a stolen vehicle loaded with firearms, and threats from her spouse of both "suicide by cop" and a mass shooting. Henderson police used vehicle tracking technology to locate the stolen SUV at the parking garage of Sunset Station casino. Allison Howlett was found inside with loud music playing, refusing to surrender. Officers eventually convinced the suspect to lower a window by offering water before pulling Howlett from the vehicle and deploying a Taser.
Detectives recovered 22 firearms 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 at Howlett's Henderson residence uncovered 30 additional firearms, among them an M2 .50-caliber machine gun, two Colt AR-style rifles equipped with M203 grenade launchers, seven suppressors and thousands more rounds of ammunition.
A Counterterrorism Escalation
Henderson Police Chief Reggie Rader told reporters at a Tuesday news conference that Howlett had been sitting on a handgun inside the vehicle and had access to a fully automatic, silenced MP5-style machine gun in the back seat — details he said corroborated the reported threats. As the investigation's scope became clear, Henderson police brought in 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 found evidence of threats extending back over an extended period. Audio recorded in 2024 and played at the news conference captured an individual warning that hundreds of people would lose their lives if the FBI did not act. Koren tied the urgency of the response to the shadow of the 2017 Route 91 Harvest festival shooting — the deadliest mass shooting in modern U.S. history — which unfolded on the same Strip Howlett allegedly targeted.
Charges and a Contested Account
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, and multiple weapons offenses. A Clark County judge set bail at $500,000.
Julie Howlett told FOX5 Las Vegas that the 22 firearms in the stolen vehicle were her inventory as a gun dealer being prepared for transport out of state, and that the dispute began when she discovered Allison using her credit card without permission. In a recorded interview with detectives, Allison Howlett denied planning a mass shooting, attributed threatening statements to false accusations from users on the platform Discord, and said her personally owned firearms had been legally transferred to Julie through an ATF-approved process.
Undersheriff Andrew Walsh said the case illustrates how quickly the window between a credible threat and a potential attack can close, urging residents to report concerns immediately. With the Fourth of July approaching, law enforcement agencies across Southern Nevada said they remain on heightened alert.