Published on: June 30, 2026, at 11:39 AM.

Updated on: June 30, 2026, at 11:53 AM.

• Authorities revealed on Tuesday that a woman was arrested over the weekend on charges of attempting to orchestrate a mass shooting.
• More than 50 weapons were discovered in her residence and vehicle.
• She was taken into custody on Saturday, June 27, in the parking lot of Sunset Station Casino located in Henderson, Nevada.

A woman alleged to be plotting a mass shooting was arrested over the weekend after law enforcement intercepted her in a casino parking structure with a sizable collection of firearms, officials announced on Tuesday.

Authorities from Henderson, Nevada, reported that the situation escalated on Saturday, June 27, when a woman dialed 911 at 9:38 AM, claiming her ex-partner, 36-year-old Allison Howlett, had stolen her vehicle, which was loaded with numerous firearms. The caller informed dispatchers that Howlett had made threats regarding a mass shooting and expressed intentions of “suicide by cop.”

Officers arrived at the caller’s residence around 10 AM and determined that the vehicle had a GPS tracker. The coordinates indicated the vehicle was near Sunset Station Casino, situated approximately 10 miles southeast of the Las Vegas Strip.

By 11:17 AM, Henderson police, in conjunction with Sunset Station security, located the vehicle in the parking garage. Howlett was in the driver’s seat listening to loud music and ignoring multiple requests to exit. Officers strategically positioned patrol cars around the vehicle to restrict her escape.

Negotiators eventually persuaded Howlett to partially lower her window. When she asked for water, they seized the opportunity to grab her hand and tased her, enabling law enforcement to pull her from the vehicle.

Considerable Firearm Cache Discovered

Law enforcement recovered 22 firearms and hundreds of ammunition rounds from the vehicle, which included a handgun beneath her and a fully automatic, silenced MP5-style submachine gun in the back. A subsequent search of her Henderson residence revealed an additional 30 firearms — including automatic rifles, suppressors, and high-capacity magazines — totaling 52 firearms.

Post-arrest, Henderson police informed the Las Vegas Metropolitan Police Department’s Southern Nevada Counter Terrorism Center, which identified a history of threats made by Howlett over several years. This included explicit comments about her desire to become an active shooter. During a briefing on Tuesday, authorities played a 2024 audio recording featuring a voice they linked to Howlett, which threatened a mass attack if federal agents failed to intervene.

Officials are continuing to investigate her motives. FBI Special Agent in Charge Christopher Delzotto praised the quick collaboration between Henderson police, LVMPD, and federal agencies for averting a potential mass-casualty scenario.

Howlett is now in custody at the Clark County Detention Center and is facing multiple charges, including making threats related to terrorism, assault with a deadly weapon against a domestic partner, grand larceny of a vehicle, firearm theft, and resisting arrest while armed.

An arraignment has been scheduled for 9 AM on Wednesday, July 1, in Henderson Justice Court. Federal charges are pending.