What's up? >> That moment detectives realized they made a mistake letting Julissa go. And while some detectives drive Julissa home, while the others storm back to her apartment, this time to put HER IN HANDCUFFS. >> POLICE COME TO THE DOOR! POLICE COME TO THE DOOR! >> BUT WHEN THE DETECTIVES STEP INSIDE the apartment, they notice that Julissa has vanished. And as they move through the rooms, one detail in the home immediately grabs their attention. >> Yeah, there was a washer going. >> Where's the washer? >> It's right here. >> Inside the washer, detectives discover bloody clothes tumbling in the drum. And the machine, still running, tells them that Julissa can't have gone far. To pin down her timeline, they pull the building's CCTV, hoping it shows when she walked out. The footage shows that Julissa isn't alone. She's seen leaving with an unidentified man just 30 minutes before detectives arrive. Now detectives have two urgent questions. Who is he? And where are they headed? Detectives quickly collect the trash bags and expand their search to every nearby dumpster, leaving no stone unturned. And what they uncover inside will change the course of the investigation. >> He's so pissed. >> The search uncovers horrors across multiple dumpsters, each one revealing something worse than the last. In one, detectives find a child's booster seat soaked in blood and torn apart by a shotgun blast. In another, they discover backpack, blood, bone, and what appears to be more brain matter. And scattered in a different bin is kindergarten homework. But it's what's inside the backpack that finally stops everyone cold. A school ID card of a 6-year-old kid named Eli Hart and his mother's name, Julissa, printed right beneath it. Piece by piece, the child's identity and the brutality he faced becomes unmistakable. Minutes later, detectives spot both of them near the complex. >> Exactly. PUT YOUR HANDS UP. HANDS UP. GET ON THE GROUND. GET ON THE GROUND. ON THE GROUND. LAY ON THE GROUND. >> WHAT AM I UNDER ARREST WE HAVE anything on her. >> What did you do with the boy, sir? >> What the [ __ ] is going on? >> We'll explain to you at the police department. >> I didn't do anything. >> No, what the [ __ ] is going on? Seriously. >> You'll be explained to you at the police department. You're being detained right now. >> For what? >> The investigation is getting increasingly disturbing with each step. But talking to Julissa is about to be an absolute rollercoaster for the detectives.