A New York man accused of posing as a federal air marshal after being pulled over with an assault weapon, ammunition and body armor in his car has been charged with weapons possession and other crimes.

Investigators say Mark Vicars produced a fake shield and credential when he was stopped on Dec. 3. Prosecutors say he had another 8,300 rounds of ammunition and other weapons in his Syosset (sy-AH'-seht) home.

Vicars pleaded not guilty Tuesday to weapons possession, criminal impersonation and other charges.

A judge set bail at $750,000 or $500,000 bond.

Vicars could face up to 15 years in prison if convicted of the most serious charges. His attorney hasn't returned a call for comment.