A 30-year-old faces charges in connection to car arsons that happened in June in Port Chester.
Fredy Hernandez-Pas was charged with nine counts of arson in the third degree, a felony.
Police say a search after his arrest found a 30-round magazine with armor piercing bullets but no weapon, however.
That finding added a charge for a large capacity ammo feed device.
Investigators say Hernandez-Paz admitted to it but did not explain his motive.
He was arraigned in Rye Town Court and released with a future court date.