Boston Police made two arrests in Mattapan early Sunday morning while responding to a report of shots fired near 45 Spencer St.

At around 3 a.m., police claim they noticed a group of men acting suspiciously and in a hostile manner.

Two of the men walked away from the group and after a conversation with an officer in a cruiser, started down Spencer Street. Officers monitored these men, who continuously looked over their shoulders and at the officers and adjusted their waist bands of the pants. 

The two men then ducked down an alleyway and reappeared in about 30 seconds time. Officers investigated the area and found a loaded silver Jennings 9mm between two trash cans.

Officers stopped and arrested 23-year-old James Mendes of Dorchester and charged him with unlawful possession of a firearm, unlawful possession of ammunition, carrying a loaded firearm and armed career criminal.

The second man, later identified as Jamall Leslie of Roxbury, was wearing a GPS tracker as a condition of probation for a prior charge. He was charged with violating his probation.