The former New York City police officer who allegedly stormed into South Orangetown Middle School with a gun pleaded not guilty to kidnapping and other charges Tuesday.

Peter Cocker appeared at the Rockland County Court in New City handcuffed in an orange jumpsuit while his attorney entered the not guilty plea to charges of kidnapping, criminal use of a firearm and burglary.

Cocker was arrested during a confrontation June 9 at South Orangetown Middle School. Police say Ken Mitchell, the school district superintendent, tackled and disarmed him after Cocker entered the school with a gun. Officials say Cocker had a sick child and was upset over a swine flu letter Mitchell had sent to parents.

Cocker, of Tappan, faces up to 25 years in state prison if he's found guilty.