Explosive device, bomb-making materials found in Pleasant Hill; man arrested charged

An explosive device and bomb-making materials were found in Pleasant Hill Friday, police confirm. One man has been arrested. A shelter-in-place and evacuation orders have since been lifted.

About 20 apartment units were included in the evacuations, police said. 

A Pleasant Hill police spokesperson said at 3 p.m., they went to a home on the 300 block of Longbrook Way to carry out a search warrant for vandalism cases. A police sergeant said the vandalism happened in Pleasant Hill and Clayton. Clayton police and the Federal Bureau of Investigation were assisting in the operation. 

Upon further investigation, an incendiary device along with the bomb-making materials were found in the person's apartment. A 27-year-old man was taken into custody.

The Walnut Creek bomb squad and Contra Costa County Fire Protection District were also called. A bomb specialist from the FBI was also on hand as authorities worked to secure the scene.  

Hazmat units were called in, according to Contra Costa Fire. Those units were cleared. 

The emergency orders were lifted around 8:30 p.m. At that time, evacuated residents from Ellinwood Apartments were allowed to return home, according to Pleasant Hill police. 

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Pleasant Hill police Sgt. Janayla Pierson said there were six vandalism cases in Pleasant Hill. Investigators connected those vandalism incidents to two that happened in Clayton. 

Neighbors at the apartment complex said police knocked on their doors to evacuate residents, who were not told what exactly the situation was at first. Many residents sheltered at the apartment complex's recreation room. 

Police said the suspect was tracked through his vehicle. They had learned he had purchased bomb-making materials. That's when the FBI was called and the warrant was served. The suspect was found at home along with the evidence. 

Neighbors said the man was quiet and kept to himself. 

"He had not lived here very long. He was very quiet and somewhat secretive," said Maureen Killmurray, who lives at the apartment complex. She said he put plastic over his windows so that people couldn't see inside. 

Police have not identified the person in custody, although they said he was booked into the county jail for one charge of possession of bomb-making materials. There could be more charges coming related to the vandalism cases. 

KTVU's Jana Katsuyama contributed to this report.