The robbery was reported about 9:15 a.m. at the Eastern Bank at 250 Elm St., Police Chief Thomas Pasquerello said in a phone interview. Pasquerello did not disclose how much cash the robber made off with.
The suspect was described as white, in his 40s, about 5 feet 8 inches tall with a muscular build and a tattoo on his right bicep, the police chief said.
In the last roughly two months, police have investigated four robberies, and made arrests in all of them, Pasquerello said.
If anyone has seen the man pictured, they are asked to call the Somerville Police at 617-625-1600.
Matt Byrne can be reached at firstname.lastname@example.org.