The Exterminator

S1 E3: As Liv and Detective Babineaux investigate a hit and run case, they discover the victim was a sociopathic hit man responsible for the murder of a tech entrepreneur, a case that Peyton (recurring guest star Aly Michalka) is prosecuting. Liv and Ravi dig deeper into a supposed zombie sighting that was posted online, which leads Liv to make a surprising discovery about someone from her past. Major moves on with his life and Peyton is shocked by Liv's reaction.