Jan Schumaker (Leigh Ann Larkin) is a hidden villainess from "Mirror, Mirror," episode 4.10 of NCIS: New Orleans (airdate December 12, 2017). She was introduced as an AUSA attorney presiding over the case regarding former mayor Douglas Hamilton, who was being released from prison after making a deal.
In actuality, Jan was actually a hired assassin hired by judge Edwin J. Miller (Hamilton's partner in the infamous Clearwater incident), to kill Hamilton. She had actually killed the real Jan Schumaker and took her identity, and she was enlisted to kill Hamilton once he was released. Another conspirator was killed, with Charlie Fournier, a DA's assistant and friend of Dwayne Pride, revealed as the assailant. Pride decided to run an operation to catch Charlie, which had the pair at the courthouse planning to kill Hamilton.
At that moment, Jan left the proceedings and pulled the fire alarm as a distraction, after which, Pride, Charlie, and Hamilton went to an undisclosed room. Pride had his gun pointed at Hamilton, only to hold Charlie up and demand the name of Hamilton's partner. It was at this point that Jan shot Charlie to death, marking her reveal as a villainous hitwoman and leading to a gun battle. After ditching her weapon, the evil Jan informed oncoming police that Pride had killed Charlie and abducted Hamilton before she made her escape. Though Miller was revealed as Hamilton's partner at episode's end, and Hamilton was sent back to prison, Jan's fate remained unknown.