Published: Aug 27, 2010 4:48 PM EDT
Updated: Aug 27, 2010 1:48 PM EDT

TAMPA, Fla. (AP) - A 17-year-old Tampa student has been arrested for allegedly trying to organize an attack to surpass the country's worst cases of school violence.

Austin James Cook was arrested this week just before classes began at Leto High.

He's being held without bail, and investigators want Cook tried as an adult on charges of solicitation to commit murder and threatening to discharge a destructive device.

A witness told investigators Cook said he wanted to "break the record" of the 1999 Columbine, Colo., and 2007 Virginia Tech shooting rampages.

Cook told deputies he was only joking, and his mother calls the allegations ridiculous.

A .22-caliber rifle was seized from Cook's room, but the boy's mother says it's a rusted old family heirloom. Also taken were a bow and arrow and several books about firearms.