ANAHEIM  (AP) — More than 100 raucous protesters heckled police officers Tuesday for fatally shooting two suspects in separate incidents over the weekend, including an unarmed man running from officers.

"Shame on you," the crowd shouted as motorcycle officers rode by.

Police stepped up patrols and some donned riot gear outside City Hall on the fourth consecutive night of protests. The building was packed with people trying to get inside where the City Council was expected to discuss a spike in shootings by officers this year.

Theresa Smith, whose son was killed on Dec. 11, 2009, by Anaheim police officers at a Walmart store, said she was astounded by what she saw at the scene of Saturday's shooting of Manuel Diaz, 25.

"There were pieces of brain on the ... darn grass, in front of all these children, in front of all these people," Smith said. "This traumatizes people and these people are angry."

Diaz's family filed a civil rights lawsuit Tuesday seeking $50 million in damages from the city of Anaheim and its police department, claiming he was shot in the back, said lawyer James Rumm.

Another suspect was killed by police Sunday after he allegedly fired at officers. That death marked the fifth this year out of six shootings in a city better known as the home of Disneyland. There were four shootings by officers last year, Sgt. Bob Dunn said.

Mayor Tom Tait said allegations that Diaz had been shot in the leg and in the back of his head was "unsettling."

The Anaheim police union defended the officers Tuesday, saying both suspects were gang members with criminal records. The union also said that Diaz was shot after pulling an object from his waistband — a common place where gang members hide guns.

"I believe that the independent investigations by the Orange County district attorney's office into both incidents will show no wrongdoing by these officers," said Kerry Condon, the police association's president.

Anaheim is a city of contrasts that ranges from upscale, hilltop homes to packed, gritty apartment complexes. The city 25 miles southeast of Los Angeles is known as home to the Angels baseball team, and above all, as the destination of Disney lovers. As California's Latino population has grown, so has the city's, hitting nearly 53 percent in 2010, census figures show.

Last month, Anaheim decided to look into hiring an independent investigator to review shootings by police amid protests by relatives of those previously killed by officers' gunfire.

Tait has also called for federal and state probes into the Saturday shooting and Latino activists have also called for a federal investigation into Saturday's shooting in broad daylight.

"People are saying, 'you know what? We have to stop this,'" said Benny Diaz, state director of the League of United Latin American Citizens in California. "As an organization we are trying to find peace but there comes a point where you have to stand up strong."

He said he wants a citizen review commission to keep tabs on the police department, officers to undergo sensitivity training and federal officials to investigate.

Tait urged the community to remain calm and tried to reassure Latinos.

"If the Latino community is saying there is a rift, then there is rift, and we need to address that," he said.

Diaz's death sparked three nights of protests. On Saturday, angry demonstrators hurled rocks and bottles at officers who were securing the scene for investigators, and police responded by firing bean bags and pepper balls at the crowd.

On Sunday, protesters swarmed police headquarters during a news conference and later set fire to a trash bin and pushed it into the street outside the apartment complex where Diaz was killed. On Monday night, Diaz's mother was joined by the relatives of others killed in police shootings in a march near where her son was shot.

Police Chief John Welter said Saturday's incident occurred after two officers approached three men who were acting suspiciously in an alleyway before running away. One of the officers chased Diaz to the front of the apartment complex.

The chief said Diaz failed to heed police orders to stop and threw something on the roof of the complex that contained what officers believe to be heroin, Welter said.

Both officers were placed on paid leave pending an investigation.

The second shooting occurred Sunday when officers spotted a suspected gang member in a stolen sport utility vehicle. A brief pursuit ended when three people jumped from the vehicle and ran. One suspect fired at an officer and the officer fired back, killing the gunman, who was identified as 21-year-old Joel Mathew Acevedo, authorities said.

Both incidents were under investigation by the district attorney's office. The FBI is reviewing whether a civil rights investigation is warranted, spokeswoman Laura Eimiller said.