Five people are under arrest-- one of the raids occurred early Thursday morning in Marin City, where residents at an apartment complex told ABC7 News the police raid looked like a military invasion.
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"It looked like something you see in a movie," said Beverly Freeman. "It was police everywhere."
"How they came here this morning, the level of humiliation, and degradation that commenced, there is nothing that could justify that," added Sharika Gregory.
Contra Costa Co. sheriffs confirm the arrest of five individuals in the murders at an Orinda Halloween party - all young men in a series of coordinated raids in four cities. Four of them are being held without bail on murder and conspiracy charges. One as an accessory.
The five suspects are identified as:
Five people were killed on Halloween night as the party at an Orinda home erupted in gunfire just before 11 p.m.-- three others were hurt. ABC7 News has learned that the violence may have stemmed from a dispute involving rival gangs, including from San Francisco.
The raid was conducted primarily by Contra Costa County Sheriffs Deputies, but the FBI and other Bay Area agencies have assisted in the investigation.
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Orinda Mayor Inga Miller expressed relief at the progress in the case that has shaken her community.
"I think in this time of uncertainty, people feel fear, they feel many emotions," said Miller. "They feel sadness for the victims in this case, and fear for a shooting anywhere."
Late Thursday, Contra Costa County sheriff David Livingston revealed that two of the victims at the party were themselves armed.
Livingston said that may have "played a role in the tragedy." He promised more details in the days to come.