A coalition of federal, state, county and Oakland law enforcement officers served over 20 search warrants and arrested at least 16 people connected to the East Oakland “Case Gang” Friday morning, as part of the city’s Operation Ceasefire.

More than 160 federal agents were involved in the effort to dismantle the Case Gang, which operates in East Oakland and has been linked by police to attempted murders as well as to robberies and pimping and prostitution. The operation stems from an October 2012 “call-in,” during which members of 14 different East Oakland gangs were told to turn their lives around with support from the community, or else get increased attention from law enforcement and prosecutors. The call-in is the lynchpin of Operation Ceasefire, a nationally-known violence cessation program in which gun violence offenders are given the opportunity to change their behavior and receive community aid and access to social services.

“We called them in, and we gave them a simple message,” said Oakland Police Department Deputy Chief Eric Breshears. “The message was ‘Stop the violence, change your lives or law enforcement will relentlessly make all efforts to shut down or dismantle your gangs.’ Today was the follow through of that promise.”

Speaking during a Friday morning press conference. Oakland Police Chief Howard Jordan thanked the partners in the operation and said the effort is representative of the enforcement aspect of Ceasefire. “We will use every legal means possible to identify those involved in violent crime and bring them to justice,” he said, standing alongside high-ranking state law enforcement officials like California Attorney General Kamala Harris and Melinda Haag, U.S. Attorney for the Northern District, in addition to representatives from agencies like the FBI, California Highway Patrol and California Department of Justice.

Jordan said that after the October call-in, there was a 10-day period when East Oakland saw no shootings. Then it started again, between the Case Gang and its rival, the “Money Team.” These groups “self-selected” as the focus of OPD attention, Jordan said.

A month ago, OPD began almost daily monitoring of the gangs, which during operations prior to Friday morning’s raid resulted in 33 felony arrests, 26 recovered firearms, 16 search warrants and eight pursuits with no major injuries or uses of force, Breshears said. The majority of the 24 search warrants, 21 of which were served simultaneously to Case Gang members on Friday, were served in Oakland, although there were a few were in Brentwood, Antioch and Pacifica. Warrants included charges of conspiracy to commit murder, possession of firearms, pimping and prostitution, robbery and attempted murder.

“They’re probably the most violent group of people I’ve seen in my 25 years,” Jordan said of the Case Gang. He added that the group was responsible for much of the violent crime in Oakland, though he said he could not give specific figures.

The gang is an offshoot of the “Nut Case Gang,” an Oakland gang from the early 2000s, said OPD Lt. Tony Jones, who oversaw the daily investigative aspect of Friday morning’s operation. The “Nut Cases,” as they referred to themselves, were infamous for a 10-week crime spree in late 2002 and early 2003 that left five people dead and many wounded. Their target locations were random, ranging from the Oakland Hills to West Oakland and Lake Merritt. The members were eventually arrested and prosecuted; most recently, in 2011 one of the gang members was convicted of first-degree murder.

Several weapons were also recovered during Friday’s pre-dawn operation, including at least one stolen firearm, handguns and one handgun with an extended magazine, Breshears said.

“We believe this operation prevented shootings, possibly homicides, and street robberies,” he said. “This operation also confirmed to us that we had the right groups. We found out fairly quickly that these groups every day were planning on ways to commit violent acts in the community of Oakland.”

Community members and state officials present at the press conference praised this morning’s operation. “As clergy, too often we are involved with the impact of gun violence,” said Rev. George Cummings of Imani Community Church, located in East Oakland, who is also the chair of the Ceasefire community working group in Oakland. “We’ve done too many funerals—far too many have died and far too many are on the edge of death. If we can come together as collaborators with the community, law enforcement and social services, we can make an impact.”

Rev. Damita Davis-Howard of East Oakland’s 1st Mt. Sinai Church and a leader in the community Ceasefire program, referenced a religious book in which God tells his people that they have the choice between life and death, blessings and curses.

“What we’re saying to the folks out there who choose death by picking up a gun is that we want you to choose life, which is, a way out of the life you’re living right now,” she said. “If you don’t choose life, if you continue to choose death, you’ll face the wrath of law enforcement.”