A man’s alleged threat to blow up the courthouse led to his arrest and the closure of a section of Highway 20 for four hours Monday as bomb technicians searched his car for explosives, according to the Oak Harbor police.

The Washington State Patrol’s interagency bomb squad responded to the scene and used a robot to inspect the man’s car, but nothing explosive was found, Police Chief Kevin Dresker reported.

Dresker explained that police received a report from an attorney that 61-year-old Ronald Bone had threatened to shoot cops and blow up district court in Oak Harbor where he had a hearing on Tuesday, Sept. 27. Officers were looking for him on Monday and found him at the Wendy’s drive-thru at the south end of the city.

Police pulled Bone over in front of Sally’s Beauty store as he was leaving. Bone told the officers that he didn’t have any explosive devices and didn’t plan on blowing anything up, according to Dresker. He didn’t want to get out of his car and took a swing at an officer, but missed, the chief said. Officers arrested Bone on suspicion of making a bomb threat and assault in the third degree, according to the Island County jail roster.

Out of an abundance of caution, the police asked a Navy team to respond with a bomb-sniffing dog. After all, Dresker said, officers didn’t want to take the chance of towing a car through town if explosives were inside.

The dog alerted on the trunk of the car, which necessitated a full-blown response. Nearby businesses were evacuated and the section of the highway was closed and rerouted onto Southwest Bayshore Drive. The highway was closed from about 3:30 to 7:30 p.m. — during Oak Harbor’s version of rush hour — and caused a traffic snarl south of the city.

Dresker said the Navy’s full explosive ordnance disposal team wasn’t in town, so the the State Patrol’s bomb squad was called. They traveled from the Everett area to get to Oak Harbor.

The robot and bomb techs found a large variety of property and junk in the car, including a propane tank, but no bomb.

Dresker said it’s unclear what caused the dog to alert on the car. It could have been that ammunition or black powder had been in the trunk at some point in the past, but police will likely never know, he said.

Bone was arrested in April for allegedly going into a woman’s home and discharging pepper spray on the walls and pointing a rifle, which turned out to be a BB gun, according to court records. He was charged in district court with unlawful display of a weapon and assault in the fourth degree.