Mother arrested in Philadelphia school attack plot

PHILADELPHIA (Reuters) - The mother of a 14-year-old boy who confessed to planning an armed assault on a Pennsylvania high school was arrested on Friday on suspicion of buying a rifle for her son, police said.

The rifle was part of an arsenal the boy had amassed including home-made hand grenades, knives, swords and about 80 pellet guns, police said.

Michele Cossey, 46, of Plymouth Township, will face charges including providing a firearm to a minor and contributing to the corruption of a minor, said Joe Lawrence, deputy chief of police in Plymouth Meeting, Penn.

The boy, who has not been identified by authorities because of his age, appeared at a delinquency hearing on Friday. He faces charges including criminal attempt and possession of a criminal instrument.

He was arrested late on Wednesday and told police he had been planning a "Columbine-type attack" on Plymouth-Whitemarsh High School in suburban Philadelphia, modeled on the 1999 Colorado school shooting in which two students killed 13 people.

The boy also kept a rifle and a pistol at the home of a family friend, Lawrence said. The homeowner turned those weapons in to police when the boy was arrested.

He planned to drive a car into the front door of the school and open fire, Lawrence said. Police declined to provide further details of the plot, which was not close to being executed, prosecutors believe.

Among materials found in the boy's home was the DVD of a documentary of the Columbine shootings.

The boy had been home-schooled for about the last 18 months after his parents took him out of the local middle school because of bullying.