They say he walked into the Patchogue Theatre for the Performing Arts about 4 p.m. with a back pack during a rehearsal, announced he had a bomb and ran out. No one was hurt.
Patchogue Theatre General Manager Clara Iacopelli said the man got on stage and said he was going to blow up the theater.
The suspect was detained by a patrol officer. He didn't have a bomb on him.
Suffolk County Police Detective Sgt. Daniel Molloy says the suspect isn't saying why he did it.