Oakland police said 16 people were arrested Thursday in the culmination of a lengthy investigation into gang violence in East Oakland.
Police Chief Sean Whent said at a news conference in the parking lot of the Acts Full Gospel Church of God in Christ on 66th Avenue that the probe focused on "two notorious and violent gangs, the 65th Village and 69th Village gangs."
Whent said the gangs have "a long history of violence that goes back for decades."
Capt. Ersie Joyner said police launched the investigation following the fatal shooting of 21-year-old Frank Denard in the 1300 block of 76th Avenue, near International Boulevard, on Sept. 15.
Police believed Denard was a member of the 69th Village gang and they feared his death would set off a cycle of retaliatory shootings between members of that gang and the 65th Village gang, Joyner said.
He said the probe was too large for the Oakland Police Department to handle on its own so it obtained assistance from other agencies, including the California Attorney General's Office, the FBI, the U.S. Marshals Service and the California Highway Patrol.
Joyner said police haven't yet arrested anyone for the killing of Denard, but the investigation led to the arrests today of suspects in two cold case homicides, one in 2008 and one in 2012.
Joyner said suspects were also arrested for robberies and other crimes.
He said the investigation is continuing and police hope to arrest up to 35 or 40 people in the next few days.
Police believe their investigation prevented four potential retaliatory homicides in recent months, Joyner said.
Alameda County District Attorney Nancy O'Malley said authorities won't release the names of the suspects arrested today until charges are filed against them on Monday.
Joining law enforcement officials at the news conference, Oakland Mayor Libby Schaaf said, "It does not bring us joy to be sending young men to prison, but it is necessary to help end the gun violence in Oakland."