The man who threw a window-rattling explosive under a Sonoma County sheriff’s patrol car parked outside a Safeway store in Guerneville last week allegedly targeted the vehicle because he dislikes the Sheriff’s Office, authorities said Monday.

Tristan Proto, 22, of Santa Rosa, took methamphetamine with a friend Friday morning in Forestville before they headed into Guerneville, Sheriff’s Sgt. Spencer Crum said in a statement. The pair parted ways after getting into a argument in town, at which point Proto allegedly lit the device, Crum said.

“Proto decided to light the firework and throw it under the vacant patrol car because he doesn’t like the Sheriff’s Office,” Crum said in a statement.

Proto described the explosive as an M-80 firework, though the Sheriff’s Office was not able to say exactly what type of explosive was used. M-80s are listed as illegal explosives by the Bureau of Alcohol, Tobacco, Firearms and Explosives.

The explosion happened shortly before noon while a sheriff’s deputy visited the store. An off-duty Napa County sheriff’s deputy helped stop Proto after the explosion by tackling him to the ground.

No one was seriously injured, though emergency responders reported a Safeway employee was knocked over by the blast. Authorities evacuated the store and closed off a block of Main Street.

The Sheriff’s Office said investigators do not believe Proto was connected to a pipe bomb found under the nearby Monte Rio Bridge last month. In the July 7 incident, about 100 people were evacuated from a Russian River beach when a passerby noticed a 5-inch-long pipe on the ground near the bridge.

No additional explosives were found by deputies when they searched Proto’s home and car, though an X-ray of his backpack led deputies to find other items that resembled explosives, Crum said. The Sheriff’s Office Bomb Squad used a water cannon to render the bag safe.

Proto remained in jail Monday and was scheduled to appear in front of a Sonoma County Superior Court judge on Tuesday. He was arrested on suspicion of using an explosive with the intent to injure and for breaking the terms of his probation.

The Sonoma County District Attorney’s criminal case search shows a 2017 conviction for resisting arrest, a incident handled by the Santa Rosa Junior College Police District.

He was previously sentenced to two years probation in September 2016 for two separate cases. One involved possession of a controlled substance while the other was related to resisting arrest, the Sonoma County Superior Court website shows.

The friend who accompanied Proto, identified by the Sheriff’s Office as Alexandra Bodrov, 22, was also arrested and booked into jail on suspicion of being under the influence of narcotics. She was released after posting $1,000 bail, the press release said.

You can reach Staff Writer Nashelly Chavez at 707-521-5203 or nashelly.chavez@pressdemocrat.com. On Twitter @nashellytweets.