An aggressive social media campaign helped Bedford police arrest a Dorchester man suspected in a bank robbery just hours after the crime occurred.

Joseph Barrett was arrested at his place of employment on South Road and charged with one count of armed robbery, police said in a press statement yesterday.

"I wish to commend the members of the public who recognized this dangerous individual on social media and undoubtedly led us to a quick arrest in this case," Chief Robert Bongiorno said in a statement. "The kinds of police-public partnerships we have developed in Bedford, using the social media tools at our disposal, are invaluable."

According to Bedford police, Barrett walked into a Bank of America branch on The Great Road at 12:13 p.m. Monday, demanding money and claiming he had a firearm.

The police department then posted the suspect’s description along with surveillance photos taken from inside the bank to Facebook and Twitter.

Bedford police said yesterday that Barrett was arrested without incident just three hours after the robbery, and he was to be arraigned today in Concord District Court.

Editor’s note: This story has been updated since it was originally published on Aug. 12.