(CNN) -- A charge of making a false bomb threat has been dropped against a man who carried a backpack containing a rice cooker near a crowd marking the first anniversary of the Boston Marathon bombings in April, prosecutors said Wednesday.
Investigators dropped the charge because they say the suspect, Kevin Edson, 25, did not communicate an "overt threat that an incendiary device would be detonated," Jake Wark, a spokesman for the Suffolk County district attorney, told CNN.
Edson was arrested after carrying the backpack with a rice cooker near the finish line on Boylston Street in Boston while survivors of the 2013 bombing were commemorating its anniversary on April 15.
In the 2013 attack, two pressure-cooker bombs exploded, killing three people and wounding at least 264 others.
A barefoot Edson, carrying a backpack and wearing black clothes with a veil and hat covering his face, screamed and yelled near the end of the anniversary event on Boylston Street, drawing officers' attention, police said.
Wark said prosecutors decided to drop the charge after reviewing statements Edson made at the scene as well as video shot by onlookers.
Edson still faces charges of disturbing the peace, disorderly conduct, disturbing a public assembly and possession or use of a hoax device. His next court date is scheduled for August 27.
The charge of making a false bomb threat carried the most severe sentence upon conviction -- up to 20 years in prison. Possession or use of a hoax device carries a maximum sentence of five years, Wark said.
A judge in April set bail at $100,000 for Edson. The judge also ordered Edson, also known as Kayvon Edson, to be seen at a state hospital that evaluates defendants' sanity after a mental health professional told the judge that Edson has a history of psychiatric disturbances.
Defense attorney Shannon Lopez did not immediately return calls seeking comment.
CNN's Jason Hanna contributed to this report.