OAKLAND, Calif. (AP) - Heavy police presence greeted Bay Area Rapid Transit commuters Thursday after more than 100 people were arrested in violent protests over the police shooting of an unarmed man.

The unruly protesters, responding to the Jan. 1 BART police shooting of Oscar Grant, smashed store windows, burned cars, and vandalized a police cruiser. Charges against them include inciting a riot, assault on a police officer, vandalism, rioting and unlawful assembly, said Oakland Police spokesman Jeff Thomason.

Police officers patrolled BART headquarters Thursday to ensure calm during the agency's morning meeting, where many African-American community leaders expressed outrage over the killing of Grant, who was black.

What had started as a peaceful demonstration over Grant's shooting death escalated Wednesday. Police in riot gear threw tear gas and started making arrests as they tried to break up the demonstration.

“The crowd started to become more agitated, more hostile, started throwing stuff at the police,” Thomason said.

An officer idenitified as Johannes Mehserle shot Grant, 22, on a Bay Area Rapid Transit station platform after responding to reports of men fighting on a train. Officers had pulled Grant and a few other men out of the train. The victim was lying face down on the platform when he was shot.

The shooting and events leading up to it were captured on amateur videos that have been broadcast on television.

Mehserle, 27, resigned from the transit agency shortly before he was supposed to be interviewed by investigators Wednesday. Mehserle's attorney did not respond to calls for comment.

Grant's family has filed a $25 million wrongful death claim against BART, and they want prosecutors to file criminal charges against Mehserle.

“There were racial slurs directed at the young men,” family attorney John Burris said Thursday. “But I have no evidence that this particular officer (Mehserle) directed racial slurs towards Oscar Grant.”

Police have not classified the confrontation as a hate crime.

Some experts who viewed the video clips speculated that Mehserle fired his gun because he believed Grant had a deadly weapon, while others think the officer had mistakenly his handgun for a stun gun.

“If he was under stress, he would not be able to distinguish between a Taser and his firearm,” said Bruce Siddle, founder of PPCT Management Systems, an Illinois company that trains law-enforcement officers in use-of-force.

Oakland Mayor Ron Dellums went to the protest scene Wednesday night to call for calm. He then led a group toward City Hall and spoke to them.

“Even with our anger and our pain, let's still address each other with a degree of civility and calmness and not make this tragedy an excuse to engage in violence,” said Dellums, who is black. “I don't want anybody hurt, I don't want anybody killed.”

Dellums asked the city's police department to start a third investigation into Grant's killing and to treat the incident as a homicide. BART police and the district attorney already are investigating the shooting.

By TERRY COLLINS - Associated Press Writer