(NBC) — Tonight on an all-new “Dateline” — chilling video evidence and crime scene photos never seen before on TV — in the murder case of Kelsey Berreth. Berreth was a Colorado mother whose disappearance made national headlines after she was last seen grocery shopping with her baby daughter on Thanksgiving in 2018.

In an eerie video originally shown to jurors, a woman at the center of a murder investigation reconstructs the scene of the gruesome crime for investigators.

Her name is Krystal Lee Kenney — a former nurse, one-time rodeo queen, and mother of two small children. Kenny is also a key player in the murder of Berreth.

In tonight’s “Dateline” Andrea Canning asks you to decide, is Kenny a “witness… an accomplice… or something else?”

Hear from lead investigators, family members, and jurors about this stunning case that will have you guessing till the very end — and beyond.

“Dateline: Devil’s Bargain” airs tonight at 9 p.m. on NBC4.