Extra police surveillance along Talbot east of Blue Hill Avenue may have prevented a murder on Thursday, but didn't stop two men from getting shot Sunday afternoon.

The Police Department says officers have stepped up surveillance there because of "a few recent incidents of firearm related violence in the area."

The Boston Police Department says officers on special surveillance duty Thursday night watched one man chase another into a building at Talbot Avenue and Wales Street - with one arm outstretched and clutching what appeared to be a sock.

Police say the sock was actually a covered gun and arrested Prescott Thompson, 21, of Dorchester on a variety of charges, including assault with intent to murder. Two alleged accomplices, Harvey Patterson, 21, of Dorchester, and Taylor Sinkler, 18, of Hyde Park, were also charged with assault with intent to murder.

Police say the man chased into the building reported seeing the three drive up and down the street several times and that when Thompson got out of the car and approached him, he fled inside.

On Sunday afternoon, police report, two men were shot around the corner, at 27 Kerwin St. One victim was found at the scene, the other was dropped off at a local emergency room by unknown parties, police say, adding a gun was recovered at the scene.