EL CAJON, Calif. (AP) — A 10-year-old boy is suspected of fatally stabbing a 12-year-old friend in the chest with a kitchen knife, authorities say.

The older boy died Monday afternoon at a hospital after he was taken from his friend’s home in El Cajon, about 15 miles east of San Diego, said the San Diego County sheriff ’s department. The mother of the 10- year- old was at home at the time of the stabbing, according to the U- T San Diego.

Sheriff ’s officials have taken the 10-year-old into custody. Sheriff ’s homicide Lt. Larry Nesbit says “the case will be up to the juvenile justice system.”

It remained unclear whether the boy had been booked into the juvenile detention system. The sheriff ’s office did not immediately return calls from The Associated

Press, but said in a statement early today that the boys’ identities would not be released because of their ages.

Neighbors say the 12-yearold boy lived in a nearby mobile home park but the two friends attended different schools.

A neighbor of the younger boy, 18-year-old Derek Gorton, told the newspaper he had emotional issues, and that something as small as tapping him on the shoulder the wrong way or losing at a video game could spark outrage.