Crime & Safety

Police Blow Up Small Explosive Device Found in SUV

The SUV was found in San Francisco last week, days after Dennis Hughes fled Rohnert Park after killing his mother with a baseball bat. The vehicle belonged to Dianne Hughes.

Details are emerging in the bizarre killing of Dianne Hughes, who was last week in her home on Bernice Avenue. Her son, Dennis, who was 41, killed her over alleged family tension. 

Police said early Wednesday that they discovered black gun powder, packed into a Band-Aid tin, a fuse and some gasoline in the back of the white Toyota Highlander, which went missing last Tuesday shortly after police discovered the body of Dianne Hughes, 66, in a pool of blood on her living room floor.

It was the missing vehicle that first led family members to call police last Tuesday, according to details from police released over the last week.

Find out what's happening in Rohnert Park-Cotatiwith free, real-time updates from Patch.

Lt. Jeff Taylor said the Rohnert Park Department of Public Safety and the San Francisco Police Department are still investigating a possible motive for Dennis, who was shot to death by a police sniper in his girlfriend's San Francsico apartment last Thursday.

He was firing shots from two handguns at police, and posed a "significant threat to public safety," police said. The Highlander was found parked nearby Post and Hyde streets in San Francisco after Hughes was taken out by police.

Find out what's happening in Rohnert Park-Cotatiwith free, real-time updates from Patch.

Some accounts detailed a mother who did "horrible things," to her son, while some revealed that Dennis was being forced out of his mother's home, where he lived. Some reported that tensions arose after Dennis destroyed a sentimental teddy bear that belonged to his mother.

While the investigation is onging, authorities said there isn't much left.

A bomb squad from Berkeley Police, which Rohnert Park contracts with, blew up what Taylor called the "incindiary device" found in the back of the SUV on Tuesday. Taylor said the gas and black powder were not all tied together, they were separate, like he was transporting it.

"A bomb squad from Berkeley X-rayed it and blew it up," Taylor said. "It created a fireball, but not an explosion."

Taylor said police now are processing all the related evidence, and combing through cell phone records to find out where he was each minute last week.

According to Taylor, the girlfriend of Hughes is not connected. Taylor said police have conducted two interviews with her and she hasn't been arrested.

Related content:


Get more local news delivered straight to your inbox. Sign up for free Patch newsletters and alerts.

We’ve removed the ability to reply as we work to make improvements. Learn more here

To request removal of your name from an arrest report, submit these required items to arrestreports@patch.com.