Two weeks after California Highway Patrol Officer Thomas Steiner was killed in a shooting, allegedly by an aspiring 12th Street gang member, 450 officers swept across Pomona before sunrise Monday in a "show of strength" targeting the powerful street gang.
Officers from two dozen law enforcement agencies conducted 140 raids and arrested 49 people, the majority of them 12th Street members.
But members of the city's other gangs were also caught up in the sweep, prompting at least two of them to curse Valentino Arenas, the youth charged in Steiner's killing, for the heightened police pressure.
Overall, the operation was "simply about protecting the public," Pomona Police Capt. Joe Romero told officers during a pre-dawn briefing at an auditorium on the Pomona Fairgrounds.
CHP Commissioner D.O. "Spike" Helmick, who promised a "day of reckoning" for the gang at Steiner's funeral, vowed Monday's raid "would not be the last."
"We were very careful and very specific in that we arrested people who had warrants for violating the law," Helmick said. "I hope today we sent a subtle message that our state is better than this and that we will continue to do this [target gangs] until this type of behavior ceases."
Most of the 49 arrests were for violations of probation or parole including associating with gang members and possession of drugs, pornography or weapons, such as knives, a .357 magnum handgun and a small pickax, police and parole officials said.
Three men were arrested on warrants and one man was detained on alleged immigration violations, said Fernando Rios, deputy regional administrator in charge of field operations for the division of parole of the California Department of Corrections.
Pomona Police Sgt. Joe Waltman said authorities would be sifting through a trove of gang intelligence.
"There's a wealth of information when you can go through their mail, letters or phonebooks," Waltman said.
Claiming 1,000 members and associates, the Pomona 12th Street gang is one of at least 15 gangs in the city and claims as turf much of south Pomona, which includes the civic center and courthouse, where Steiner was gunned down on April 21.
Pomona's 12th Street gang -- which has close ties to the Mexican Mafia, one of California's most powerful prison gangs -- uses the shark as its symbol and has spread into western San Bernardino County. The morning of the raids, a shark fin and the number 12 could be seen spray painted at the entrance to Madison Park, a gang hangout also known as Shark Park.
Waltman said the city would continue to keep the heat on local gangs. The Pomona City Council is considering seeking a court order that would prevent gatherings of the 12th Streeters.
Asked why authorities conducted sweeps only after an officer was killed, Helmick called it "a valid question."
He said the problem in part is lack of staff. To mount a sustained campaign, however, police agencies "have to combine resources."
"It shows people have to join hands and work together," Helmick said.