Harleen Quinzel (Batman: Arkham Origins)

Dr. Harleen Quinzel was a psychiatric intern for Dr. Hugo Strange who worked in Blackgate Prison.

Batman's psychological profile
''Quinzel is finishing up her psychological residency at Blackgate Prison. It seems odd that a student would try to work at a facility that has little desire to rehabilitate its inmates, but perhaps her interest in the criminal mind will bear fruit.''

Batman: Arkham Origins
She worked as an intern under the psychiatrist Hugo Strange, and worked as one of the psychiatrists at Blackgate Penitentiary. At one point, she, under Strange's orders, contacted one of his patients, Alberto Falcone, the heir to the Falcone Crime Family, to notify him that he missed his past two appointments, and gave the subtle but clear threat that Strange and Quinzel will tell his father, Carmine Falcone, about Alberto carrying potentially untreated psychological issues if he doesn't continue his appointments.

By the time of Christmas Eve, Quinzel was nearly finished with her psychological residency at Blackgate. After Julian Gregory Day, also known as the serial killer Calendar Man, was arrested by the GCPD with the anonymous help of Batman, Quinzel did a psychological evaluation of the serial killer, and determined that Day was insane and thus could not be executed. However, Warden Joseph had her redo the evaluation under the pretense that he was manipulating her (although it was heavily implied that Joseph himself was being manipulated by Commissioner Gillian B. Loeb into having Day ruled sane and execute him to gain political points). She did so under the condition that she be allowed to do psychiatric analysis on all newcoming prisoners of Blackgate prisoners from that point onward.

After the Joker, a new criminal mastermind, was arrested by the GCPD, she did a psychiatric evaluation on the mass-murdering psychopath, also holding some sympathy for the Joker due to her belief that the GCPD was bullying homeless people. This led to the Joker to manipulate her into becoming a pawn inside the prison, which worked largely because she didn't have any friends beforehand.

Eventually, she was held hostage by the various prisoners at Blackgate when the Joker escaped and instigated a riot. The prisoners strongly implied that she leaked the security codes to the Joker after he wooed her, although she and the security staff denied it. Batman later rescued them, with Quinzel telling Batman that the Joker was waiting for him at the panopticon, although she felt uncomfortable when Batman mentioned the cops will keep her and the other staff safe. After the Joker was recaptured, Quinzel followed the staff as they escorted a restrained Joker back to his cell, also winking at him.

Trivia

 * Her character trophy reveals that a clipboard she was holding contained the classified form that Amanda Waller used to get Deathstroke to join the Suicide Squad, although it was not made clear whether she had any affiliations with the group.