The man who robbed Cambridge Trust Company three separate times last year pleaded guilty Thursday to each crime, and faces up to 75 years in prison.

Patrick M. Cannon, 57, was convicted in U.S. District Court on three counts of armed robbery.

In the latest case, on Aug. 11, Cannon entered the 65 Beacon St. bank wearing a white graduation gown. Inside he "brandished a black semi-automatic handgun and ordered the tellers to empty their cash drawers," according to an FBI press release. After robbing the bank, he fled in a black Cadillac SUV. Police found the vehicle, which belonged to Cannon's brother. The brother said he had lent it to Cannon that day.

Police arrested Cannon and he admitted to the robbery, as well as the May 14 and June 2 robberies of the same bank, the FBI said.

He is scheduled to be sentenced June 19 and faces up to 25 years in prison on each count to be followed by five years of supervised release and restitution in the amount of $30,789.