A 15-year-old Landover youth was arrested yesterday and charged with fatally beating an Army recruit at a Largo mall this month, Prince George's County police said.

Authorities would reveal no motive in the slaying of Matthew Pickett, 21, who was attacked late Nov. 5 outside the Boulevard at the Capital Centre. Pickett, who lived in Upper Marlboro and worked as a teacher's aide, died at a hospital two days later.

Police charged the youth, who was not identified, as a juvenile with manslaughter, said Cpl. Diane Richardson, a police spokeswoman. Officials declined to release further details.

Pickett's relatives were upset by the juvenile manslaughter charges, the victim's uncle, Mark Pickett, said in a telephone interview last night.

"It's a complete travesty if this kid gets manslaughter at 15," Pickett said. "We feel he should be charged as an adult because he's doing adult things."

Investigators received many tips in the case that helped identify the youth who was charged, Richardson said.

Pickett was heading for a Saturday night outing with his girlfriend to see the movie "Jarhead" when the beating occurred. Police said in earlier reports that he was struck on the back of the head with a metal pipe.