Jessica is the lead detective of this awful case. She was widowed at an early age and has one son. Has thrown herself into her job to avoid her grief. She has honed her interrogation skills to coax confessions out of the most hardened criminals. Balancing her career, Jesop's insecurities, and her family may just be too much to bear as the stress bears down on her, her coping methods collapse, and a nihilistic weight looks to drown her. After all, these killers are her kid's age, his classmates.
Jesop rides a short fuse, but these kids with their flippant attitudes towards authority are burning that fuse closer and closer to the powder keg. It doesn't help that his partner, Jessica, starts demeaning him in front of them. Jesop gets why Jessica was promoted over him and now he is just a lackey taking notes for her. But he doesn't have to like it.
Caleb is a soap washed, manicured, everything in its place, megalomaniac. When the police bring him in, the damage is done. Everything is clean and put in its perfect corner with no prints left behind. Caleb's intellect is as precise as a surgeon's scalpel.