Hillsborough, N.C. ? A teenager accused of killing his father and opening fire outside his former high school was obsessed with school massacres and sent e-mail to the principal of Columbine High School in Colorado warning of his attack, authorities said Thursday.

“Dear Principal,” the e-mail read. “In a few hours you will probably hear about a school shooting in North Carolina. I am responsible for it. I remember Columbine. It is time the world remembered it. I am sorry. Goodbye.”

Alvaro Castillo sent the message Wednesday morning, shortly before two students were wounded by gunfire in the Orange High School parking lot in Hillsborough, said Orange County Sheriff Lindy Pendergrass.

Castillo, 19, was arrested quickly, and police found two pipe bombs and two rifles in the van he was driving and four additional pipe bombs at his home, authorities said.

Castillo told deputies he had killed his father, Pendergrass said. Rafael Huezo Castillo was found shot to death in the family’s home.