EVERETT — Saturday’s shooting in south Everett that ended the life of a 17-year-old appears motivated by a gang rivalry, according to court documents released Tuesday.

There’s also evidence suggesting that gang members may try to seek revenge for Anthony Camacho’s death. The suspect’s family told detectives that the day after the shooting someone spray-painted graffiti near their home. The graffiti bears the initials of the alleged shooter’s rival gang.

Snohomish County sheriff’s deputies are stepping up patrols in the area, particularly around Mariner High School, spokeswoman Shari Ireton said. The county’s drug and gang task force also continues to monitor activity, she added.

Diego Tavares, 19, reportedly admitted to his father that he was involved in Saturday’s killing. He said prior to the shooting he’d been walking near Everett Mall Way when two carloads of rival gang members chased after him. He was able to get away and hide. He reportedly later found out on Facebook that his rivals were having a party near Mariner.

Investigators were told that Tavares allegedly admitted that he went to the rival gang’s party to “shoot them up,” Snohomish County sheriff’s detective Brad Walvatne wrote in an affidavit.

Tavares made a quick appearance Tuesday in Everett District Court. Judge Tam Bui found probable cause to hold him for investigation of first-degree murder. She set bail at $2 million. Bui prohibited Tavares from contacting anyone associated with what she called his “group.” He also is prohibited from contacting his father, a potential witness.

That man allegedly told detectives he’s afraid of Tavares, and he’s concerned that his son will harm him and the rest of their family.

Detectives were able to piece together their case without much help from anyone at Saturday’s party. The partygoers denied seeing or hearing the shooting. They also told detectives they didn’t know who was responsible.

Deputies were first alerted around 3:40 a.m. Saturday when neighbors complained of gunfire near 124th Street SW and 4th Place W. The caller reported seeing three men loading an injured man into a silver-colored car. The car was gone by the time a deputy arrived.

The deputy found evidence of a party, including beer bottles and vomit. He also noticed a shot-out window on a car parked in the driveway.

The deputy was checking the area when Swedish/Mill Creek notified a 911 dispatcher that a gunshot victim had been dropped off by three men who had left the hospital.

Camacho had a gunshot wound to the head. He was moved to Harborview Medical Center in Seattle, where he later died.

He was a student at ACES high school in the Mukilteo School District and would have turned 18 this week.

Court documents do not say if Camacho was part of a gang. His friends have said he wasn’t. They say he was in the wrong place at the wrong time.

Detectives first heard about Tavares’ possible involvement the day after the shooting. He allegedly told his uncle he wanted to travel to Mexico as soon as possible. Detectives spoke to Tavares on Dec. 14. He allegedly admitted that he knew of the shooting and a vigil for Camacho.

He “said too many young people have died recently,” Walvatne wrote.

Once detectives turned on an audio recorder Tavares declined to say more. He was arrested after investigators spoke with additional witnesses.

Hours after the shooting, Tavares was looking for marijuana, according to a Facebook account that detectives say belongs to him. The next day he posted a picture of himself with a blue bandana around his neck. He appears to be flashing a gang sign.

Tavares is a convicted felon. He attempted to rob a retired police officer, 60, in January outside the Alderwood mall. She gave chase and bystanders helped detain Tavares until police arrived. He pleaded guilty to attempted theft and was sentenced to two months in jail. He was banned from having guns.

Prosecutors have until Thursday to file charges against him in the killing.

Diana Hefley: 425-339-3463; hefley@heraldnet.com. Twitter: @dianahefley.