A bomb threat charge has been dropped against a man accused of placing a backpack with a rice cooker near the Boston Marathon finish line on the anniversary of the bombing

Suffolk County district attorney's spokesman Jake Wark said Tuesday that based on the evidence the state could not prove that Kevin Edson communicated a clear threat with an explosive device.

Edson was spotted with a backpack near the finish line April 15 wearing makeup and a black veil. A court document said the 25-year-old told police ``the performance got the best of me.''

His mother has said Edson has battled bipolar disorder. A state psychiatric hospital deemed him competent for trial.

Edson is charged with possession of a hoax device, disturbing the peace, disorderly conduct and disturbing a public assembly. He has pleaded not guilty.