Being Human S00 E10 Becoming Human: Episode 4

"Flatmates by day - undead by night."

Brandy Mulligan seems a likely suspect as Matt has recall of being in a girls' changing room so Christa and Adam pursue Brandy, pointing out that they know she is a member of the notorious Crompton family. Brandy is hostile but Matt suddenly recalls that he saw her leave the changing room so that she cannot have killed him.