Patrick Purdy was on nothing stronger than coffee and cigarettes when he opened fire with an AK-47 outside an elementary school, killing five children before committing suicide, authorities said.

Toxicology reports performed on the body of the 24-year-old drifter have revealed only "a trace of nicotine and caffeine," Stockton Police Capt. Dennis Perry said."A cigarette and a cup of coffee," Perry said. "That may be it."

Police and relatives have said Purdy had a history of drug use, and he was arrested several times on drug-related charges.