A child was charged with murder and felony assault in the fatal stabbing of a 12-year-old boy, authorities said Wednesday.
San Diego County district attorney's office spokesman Steve Walker declined to say if the defendant was the victim's 10-year-old neighbor who was taken into custody shortly after the stabbing. The neighbor is the only person who has been identified by homicide investigators as a suspect.
A detention hearing was scheduled for Thursday in juvenile court.
The 12-year-old died Monday, a little more than an hour after he was stabbed in the 10-year-old's driveway in a quiet, kid-friendly neighborhood in El Cajon, east of San Diego.
The victim slept at the boy's home for two nights before he was attacked at the end of the holiday weekend, said Cody Vales, a close friend of both boys. He said they were "like best buddies."
Vales, 16, said the 10-year-old appeared calmer since he began taking a new medication about three weeks ago, becoming "a new kid." He said the younger boy wasn't one to pick a fight but exploded when he felt provoked.
Vales said the boy once punched him in the face for accidentally bumping his pelvis when they were jumping on a trampoline. The boy threw a tantrum when he spilled a cup of water inside his house and was asked to clean up.
"If you pushed his buttons and cussed him out, he'd just lose it on you," Vales said.
The 10-year-old liked to play football and practice Muay Thai boxing and jujitsu, Vales said. He was muscular and a little short for his age.
The 10-year-old's adoptive mother, who lived with the boy and her father, was the only person who knew how to calm him, Vales said. She hugged him and reassured him that everything would be all right.
"The nicest woman you'd ever meet," Vales said. "If it was anybody else, they wouldn't be able to put up with (him)."
The victim's mother told U-T San Diego that she knew the 10-year-old and his mother well.
"Please don't make it out that he was this terrible human being," Lisa Carter told the newspaper. "He's not some monster."
The neighborhood in San Diego's foothills is one of modest, aging one-story homes on narrow, winding roads. The two boys played often with others at a playground clubhouse in the mobile home park where the victim lived. They sometimes pretended to be pirates.
It is unusual for children so young to kill. Law enforcement agencies reported 11 homicides nationwide by children 12 and younger in 2010 _ the same number as in 2009 and 2008, according to FBI data.
James Alan Fox, a professor of criminology, law and public policy at Northeastern University in Boston, said that 1976 through 2010, 242 homicides were committed in the United States by children 10 and younger, according to his analysis of FBI statistics. Of those, 48 percent of victims were family, 20 percent were acquaintances and 8 percent were friends.
Fox said there are typically no telltale signs to predict such acts of violence.
"Overwhelmingly the most common element is just an argument," he said. "It's the same motivation why kids fight."
California requires that children be at least 14 to be charged as adults, said Shaun Martin, a University of San Diego law professor. State law allows children to be detained until they turn 25 if tried and convicted as juveniles.