December 30, 2016 01:58 PM

The 2004 disappearance and death of mom Lauri Waterman rattled the small town of Craig, Alaska. But even before the truth of what happened was revealed, people were noting the behavior of her 16-year-old daughter, Rachelle.

“By [that] Monday morning, most of Craig, Alaska, knew that Lauri was missing. They were sort of surprised to see Rachelle show up at school that day,”explains PEOPLE Executive Editor Cynthia Sanz in Monday night’s episode of People Magazine Investigates, on Investigation Discovery. The episode will focus on Lauri’s murder.

“Rachelle’s emotions the day after are all over the map,” a case expert says on Monday’s episode. “At times she’s crying, at times she’s angry, at times she’s inappropriately giggling and silly.

“She’s just thinking all kinds of crazy thoughts.”

As PEOPLE Senior Editor Alicia Dennis explained during a Friday appearance on People Now, in a video above, the investigation into Lauri’s death uncovered tension between her and Rachelle.

Eventually, police said, they found a deadly bond between Rachelle’s boyfriend and his friend.

The People Magazine Investigates episode on Lauri’s death, “The Darkest of Nights,” airs Monday night (10 p.m. ET) on Investigation Discovery.

You May Like