Dianne Hughes, 66, was bludgeoned to death with a baseball bat by a son who was angry at being ordered to move out of her Rohnert Park home, according to investigators.

A day after her body was discovered on Tuesday, detectives tracked Dennis Hughes, 41, to a San Francisco apartment where he was shot to death during a police standoff.

Hughes had been living at his mother's Bernice Avenue home since January.

"He was keeping her up at night ... rummaging around the kitchen ... starting to act a little strange," Lt. Jeff Taylor of the Rohnert Park Public Safety Department said Friday.

Family members told police Dennis Hughes told his mother he'd go, but changed his mind.

"And then he destroyed sentimental property — a teddy bear from a deceased friend of mom," said Taylor. After that, she again told him he had to leave.

Tuesday afternoon officers found her bloodied body in her home. She'd suffered blunt force trauma to her head and a baseball bat was seized as evidence.

Detectives quickly traced Hughes to his girlfriend's San Francisco apartment.

Hughes wouldn't come out of the Post Street residence when detectives arrived on Wednesday. As San Francisco officers went into the apartment, he began shooting and they retreated, police said.

He also ignited least two fires in the apartment. The city's SWAT team and firefighters joined the effort and at least 180 neighbors from nearby apartments were evacuated.

Hughes fired several more times, shooting into walls, the ceiling and floor, apparently reacting to noises, San Francisco police later said.

The standoff ended when a San Francisco SWAT sniper shot Hughes. Police officials approved the shooting in advance, saying Hughes had become too much of a threat.

Hughes was found with two handguns, a semi-automatic handgun and a pistol. He'd fired 13-20 shots, according to various reports.

"They're still counting shells and bullet holes," said Taylor.

Detectives said they don't believe anyone but Hughes was involved in his mother's slaying.

You can reach Staff Writer Randi Rossmann at randi.rossmann@pressdemocrat.com or at 521-5412.