The unnamed Bank Manager was the hidden villainess from Person of Interest episode 3.12, "Aletheia".
She as portrayed by Jennifer Lim.
She was an operative for Decima Technologies who posed as a bank manager at a vault that contained Samaritan, a project created by Arthur Claypool and modified by Harold Finch to create The Machine. The villainess killed the actual bank manager, Karen Wallace, and then took possession of the Samaritan drives, while replacing them with fake ones. She was shot during a raid on the vault, and was tended to by Harold and Arthur. After Root informed them about the real Karen Wallace, Harold was shown footage of the villainess making the swap.
In the end of the episode, the evil agent was shown handing Samaritan to Greer, her superior. She was later shot and killed by Greer to cover his tracks.