Three banks in the west Valley were robbed on March 5 during a half-hour stretch.
Police said the suspect walked into the banks, approached employees and displayed a note demanding money and threatening that he has a gun and/or bomb. He took the money and fled.
Police say they received several tips from the community that led them to arrest Patrick Robert Day, 42.
Day is a parolee who has an extensive criminal history, including arrests for drug violations and violent crimes, police said.
The three banks were located in the 22800 block of Victory Boulevard, the 22000 block of Ventura Boulevard and the 21800 block of Sherman Way.