Federal investigators are asking for help catching a robber who they say may have stolen from the same Alexandria bank four times in the past three years.

The “Beacon Hill Bandit” has used the same modus operandi in all four cases, according to the FBI. Each time, the robber entered the TD Bank at 6615 Richmond Highway wearing square-framed sunglasses, looking down at his cell phone, the FBI said. He approached a teller and demand money or passed a note demanding money, along with a plastic grocery bag. In three of the robberies, he implied that he had a weapon. Afterward, he fled down the highway on foot.

The robberies took place between March 2010 and July 2013.

According the FBI, the suspect is described as a black male in his thirties, between 5’9” to 6’0” with a muscular build. Twice he was dressed as a construction worker with a yellow hard hat; once he wore a Teenage Mutant Ninja Turtles baseball cap.

The FBI’s Washington field office is offering a reward of up to $5,000 for any useful information on the so-called “bandit.”