'The Piketon Family Murders' Brings the True-Crime Chills -- Watch the Trailer (Exclusive)

'The Piketon Family Murders' victims.

The two-hour special premieres Sunday, March 31, at 7 p.m. ET on Oxygen.

You might want to watch this one with the lights on.

ET has your exclusive first look at Oxygen’s chilling new true crime special, The Piketon Family Murders. The two-hour special dives into a complicated and horrific massacre that stunned the small town of Piketon, Ohio, back in 2016. It explores the cold-blooded murder of the Rhoden family, as well as Hannah Gilley, the fiancée of one of the other victims. The massacre became the largest criminal investigation in Ohio’s history, spanning more than two years.

Legal expert Beth Karas hosts the television event, which also explores the paranoia that permeated Piketon after the murders. In Nov. 2018, arrests were finally made in the case -- four members of a prominent family in Piketon, the Wagners, were charged with first degree murder, and the residents of Piketon became torn between a developing feud among two families no one saw coming.

Community members, family, friends, local law enforcement and journalists all help Karas tell the story, which also includes the frantic 911 call, pre-trial hearings and bombshell revelations. Watch the trailer here:

The Piketon Family Murders premieres Sunday, March 31, at 7 p.m. ET on Oxygen.