The casino employee accused of slashing five of his coworkers at a California resort plead not guilty to attempted murder charges and will undergo a psychiatric evaluation following the bloody rampage.

A lawyer for Joseph Naugle, 22, requested the mental-health review in a Placer County courtroom Wednesday as the accused slasher faces several charges in the alleged attack at the Thunder Valley Casino Resort in Lincoln last week.

Naugle — who appeared in court dressed in an orange T-shirt and orange-and-white-striped pants — also pleaded not guilty and is due back before on September 2.

The psychiatric evaluation will be used to determine whether Naugle is mentally fit to stand trial.

The casino mayhem unfolded last Wednesday night when Naugle, a kitchen worker at Dos Coyotes inside the casino, allegedly knife his fellow employees in the eatery’s kitchen area.

Shocked gamblers looked on in horror as bloodied victims spilled out of the restaurant and onto the casino floor. A caller reported the incident to police, who arrived within minutes and immediately took Naugle into custody.

One victim was transported to a hospital with non-life-threatening injuries, while the four others were treated at the scene by emergency personnel. The hospitalized victim was released hours later after receiving emergency treatment.

Naugle, still dressed in his kitchen apron when he was arrested, is a resident of nearby Roseville who graduated from a local high school in 2022.

The motive behind Naugle’s alleged slashing spree is still being investigated.