Police are examining a laptop computer of a man who is suspected of gunning down three people in western Idaho in hopes of figuring out exactly why he did it.

John Lee, 29, was arrested after a high-speed chase in neighboring Washington state, hours after he allegedly opened fire at three different locations in the small Idaho town of Moscow, according to the Associated Press.

His adoptive mother, landlord, and a manager at a restaurant were all killed, and one Seattle man also received critical injuries.

Investigators searched his car and found lots of weapons — semi-automatic pistols, a rifle, a revolver, and a shot gun, according to Moscow Police Chief David Duke. They also found a laptop, and are seeking a warrant to search it.

The police will use ballistic tests to determine which weapon was likely used in the shootings.

Authorities are still in the dark on what motive was behind Lee’s actions. He left a trail of bloodshed beginning with his adoptive mother, 61-year-old Teri Grzebielski, who was found shot dead at her home. They they found his landlord, 76-year-old David Trail, dead of a bullet wood at Northwest Mutual Life Insurance. Another man who did not know Lee, 39-year-old Michael Chin of Seattle, was shot in the arm and leg while discussing business with Trail. He is currently in critical condition.

Lee then left the insurance office and headed to an Arby’s restaurant, asking to speak with a manager. When 47-year-old Belinda Niebuhr appeared, he shot her to death. According to police, the restaurant was frequented by Lee’s parents, but workers there did not recognize Lee.

An employee at a nearby cafe heard the gunshots and took down the license plate number of a car that fled the scene, reporting it to the police. Authorities spotted the car and gave chase, which lasted 25 miles and reached speeds of 100 miles per hour before he crashed over the border in Washington state.

Lee had minor injuries, and was booked at Whitman County Jail after being treated on charges of felony eluding, and Idaho authorities issued an arrest warrant for Lee on three counts of first-degree murder and one of attempted murder.