Mothers have lied, spun elaborate alibis and hidden evidence for their gang-member sons. But investigators say Eva Daley went to murderous lengths.

Daley, 30, drove her 14-year-old son and six other members of the Latin Marijuana Smokers gang to a skate park to kill a 13-year-old boy they had a grudge against, police say. The boy, Jose "Bobby" Cano, was stabbed to death.

"I'm shaking my head at this because I thought I had heard of everything," said Gary Hearnsberger, head of the Hardcore Gang Division at the Los Angeles County district attorney's office.

Daley and the seven teenagers were charged with murder in the June 26 slaying near the squalid skate park in this port city of 462,000 about 25 miles south of Los Angeles.

Daley was jailed on $1 million bail and pleaded not guilty Tuesday. The teens, ages 14 to 17, face hearings to determine whether they will be tried as adults. Police said at least three more juveniles are being sought.

Police refused to say where the mother was during the attack itself or immediately afterward. And they would not say what led to the arrests, or what the killers had against Cano.

"There is a lot of father-son gang participation, even grandfather-father-son. But it's unusual to see mothers cheering on their sons in a violent gang conflict," said gang expert Alex Alonso, who runs the Web site streetgangs.com. "They usually are naive about their son's activity, in denial. They always think other kids are involved in gangs but not theirs."

Similar cases have surfaced in recent months. In a community outside Los Angeles, a 37-year-old mother drove her son's friends to a rival gang member's home for a drive-by shooting, police said. The mother was charged with assault.

In October, police arrested a 42-year-old woman suspected of driving her two sons and three others in an SUV to a Los Angeles neighborhood to scrawl it with graffiti. The charges were dropped for lack of evidence.

Prosecutors in Long Beach said Daley drove the teenagers to the scene "in furtherance of the gang" — an allegation that could add 10 years to her 25-years-to-life sentence if she is convicted.

Police said Daley knew her son and the others planned to kill Cano.

"She wasn't taking them there to play in the park," Officer Jackie Bezart said.

Deputy District Attorney John Lonergan said investigators were still trying to determine whether Cano was a gang member or someone who had simply crossed the gang in some way.

Police and Cano's family said he had been involved in at least one previous fight with the others.

After Daley's arraignment Tuesday, a man supporting her screamed and lunged at Cano's family in a courthouse hallway and attacked a cameraman.

Standing nearby, Cano's bleary-eyed mother, who declined to give her name, said she was more angry at Daley than at those who stabbed her son.

"Taking children to do this?" she said in Spanish. "This I don't understand."