Published: Oct 07, 2010 3:48 PM EDT
Updated: Oct 07, 2010 12:48 PM EDT

STOCK ISLAND, Fla. (AP) - The Monroe County Sheriff's Office says a device that triggered the evacuation of Florida Key Community College was an extra credit chemistry project.

Chemistry professor Bruce Gragg found the device in his mail at the college on Tuesday. He placed it in a garbage can and the sheriff's office was called to the scene.

Investigators determined the device was not dangerous.

On Wednesday, 56-year-old Gary Moes of Key West called detectives to say the device was his. Moes said he was enrolled in Gragg's online chemistry class, where they were studying chemical reactions.

Moes said he'd constructed the device as an extra credit project.

Detectives are conferring with the state attorney's office to determine if any charges will be filed.