A partnership built on profit spiraled into paranoia and premeditation. When bleach, a hit list, and a gun entered the picture, it became clear this was no accident—it was an ambush. Watch “The Tech Bro Murders” Tuesday on ID and stream on @HBOMax #TheTechBroMurders | Investigation Discovery

He thought it was a simple job—just paint over a floor. But when Donnie realized what he was covering up, it was already too late to walk away. Watch “The Friday the 13th Murders” Wednesdays on ID and stream on @HBOMax. #TheFridayThe13thMurders | Investigation Discovery

On Friday the 13th, Christine Markle and her daughters are found murdered. A signed confession points to John Markle, but the blood-stained Halloween mask left at the scene raises haunting questions. Watch “The Friday the 13th Murders” Wednesday on ID. | Investigation Discovery