The video shows a person who the Waltham Police Department previously said carried out five of the assaults in a large apartment complex north of downtown Waltham between Nov. 10 and Nov. 20.
Those attacks occurred between 5:30 p.m. and 10:30 p.m., the department said.
NBC Boston reported that another five people have been assaulted in downtown Waltham since then.
The department did not immediately respond to a request seeking more details, but the station reported that one of the assaults was on a U.S. Postal Service mail carrier. A USPS spokesman did not immediately respond to a request for comment.
Another victim, David Cameros, told the station that he was struck in the head by what he believes is a bat while smoking a cigarette outside the apartment complex.
The assault left him with a fractured skull, NBC Boston reported, and photos shared with the station showed him in the hospital with a bandaged head and badly bruised eye.
In the surveillance videos, the man can be seen running and walking.
Waltham is a city of roughly 62,000 people 11 miles west of Boston.