At about 9:00 PM on Tuesday February 2, 2016, officers assigned to the City Wide Drug Control Unit made an onsite firearm arrest in the area of 1 Terminal Street in Charlestown. Officers were on directed patrol in response to recent drug and firearm related incidents in the area when they observed a motor vehicle pull into an empty parking lot for no apparent reason. Officers set up surveillance on the vehicle and observed the operator, later identified as Ullentor Santos, 23, of Dorchester, preparing a marijuana cigarette. Upon seeing this, the officers approached and performed a pat frisk of the operator and the vehicle which resulted in the recovery of a loaded Para Ordinance P12 .45 caliber handgun. The suspect was placed in custody without incident and will appear in Charlestown District Court on charges of Unlawful Possession of a Firearm and Unlawful Possession of Ammunition.