The Hawaii Five-0 episode “Na Pilikua Nui (Monsters)” takes place on Halloween. Five-0 investigates a string of murders involving female corpses with missing body parts. One victim’s ex-boyfriend — ex-con Mark Sheppard who’s a little obsessed with the paranormal — is a suspect but is ruled out when he tries to end his own life.
Mark Sheppard is portrayed by Michael Graziadei. He’s known for his roles on The Lottery (Kyle Walker), The Young and the Restless (Daniel Romalotti), The Secret Circle (Callum), American Horror Story (Travis Wanderley), Crash (Gavin Buckely), 90210 (Eric), among others. Graziadei is also recognized for his role as Darren in the 2007 film Boogeyman 2. Hawaii Five-0 airs Fridays at 9pm on CBS.