The campus of a Santa Rosa elementary school caught in the cross hairs of a gang turf war has been quiet since a suspected gang member was stabbed to death two weekends ago, the principal said Friday.

Police stepped up patrols in the wake of 20-year-old Juan Carlos Angel-Esparza's after-hours killing and detectives continue to piece together their case against Raul Vega, 19, who is in custody and charged in the slaying.

"We're back to business," Principal Jesse Escobedo said. "We just have to be alert. We have to be on our toes at all times."

Suspected gang members are staying away at night and the graffiti that was appearing on the school's walls and handball courts before the stabbing has stopped, Escobedo said.

Vega and his three co-defendants in a separate Contra Costa County homicide committed a year ago appeared in court Friday to answer to gang-related charges, including the slayings.

In addition to the Jan. 8 slaying of Angel-Esparza, Vega is the suspected shooter in the Jan. 12, 2010 killing of Vallejo musician Dewey Tucker, 24, who authorities said Vega had mistaken for a gang rival.

The shackled defendant smiled to someone in the large courtroom crowd as he was led by deputies to a seat, where he talked quietly with his lawyer, Kathleen Hernandez.

His three co-defendants in the Tucker killing - Christopher Mancinas, 29, Hector Barragan, 28, and Javier Ivan Carreon-Lopez, 20, all of Santa Rosa - sat in jailhouse uniforms nearby.

Judge Arthur Wick was expected to set a preliminary hearing date but he postponed that action until March 7 so both sides could have more time to review evidence in the two slayings. The preliminary hearing, to determine if there is evidence enough for trial, could come up to 60 days after that.

Prosecutor Bob Waner said he was obtaining transcripts of witness depositions to distribute among the defense lawyers. So far, it appears the two homicides will be tried as one case, but Waner would not discuss how or why the cases are linked.

"They are appropriately joined," he said outside of court.

According to Santa Rosa police, Vega and Angel-Esparza, both suspected of having gang ties, fought near a baseball field Jan. 8 on the campus as at least three others stood by.

Angel-Esparza was stabbed and died from a direct wound to the heart. Vega was arrested the next day near a family home at Mayette and Yulupa avenues.

Sgt. Steve Fraga of the police department's violent crimes unit said Friday the killing arose from a simmering dispute between factions of the same sureno gang over control of territory near the South Park neighborhood. Adding to tensions is the presence of rival norteno gang members nearby, he said.

Graffiti "crossouts" - where one gang marks over another gang's graffiti - is proof of this struggle, he said.

"This was a classic gang case where two gang members basically entered a confrontation with each other," said Sgt. Ray Navarro of the department's gang team. "A fight begins. One ends up getting stabbed and dies as a result."

But Vega was in trouble already, authorities said.

CHP officials said that about the same time as the stabbing, they were closing in on Vega as the possible shooter in the year-old killing of Tucker, who toured with hip-hop singer Lauryn Hill.

Charging documents in that slaying said the four men drove to Contra Costa County to seek out a rival who had threatened Barragan. They mistook Tucker for the rival and shot him as he drove on I-80.

Meanwhile, Escobedo said a police car or motorcycle was parked in front of the school all last week and officers patrolled at night.

Concerned residents have called to offer support with some discussing organizing residents into a neighborhood watch group.

"We're happy to see we're considered a viable and valuable component of the Santa Rosa community," Escobedo said. "It's a silver lining. For too long, the neighborhood has labored under the stigma of &‘Those people' at &‘That school.'"

Santa Rosa Mayor Ernesto Olivares said the neighborhood is safe.

He said a community meeting after the stabbing has helped strengthened neighborhood ties that will be important in the long run. He urged residents to report any suspicious activity to police.

"Clearly, we don't have the resources to be there all the time but they can help be our eyes and ears," Olivares said. "We need to teach them to stay engaged and talk to their kids."