It appears Jamie killed Katie after being influenced by corners of the internet that convinced him he was too "ugly" to receive affection from a woman, as he lets out in his conversation with the therapist in Episode 3. When Katie turned down his advances and bullied him with an emoji that implied he was an incel, he did something tragic.

Netflix's Adolescence ended with a twist, as it was revealed whether Jamie Miller was responsible for the murder of Katie

A former probation officer who has worked with serious offenders like Jamie from Adolescence has explained why he kept telling the psychologist that he’s ugly. The current most-watched show on Netflix follows 13-year-old murder suspect Jamie Miller,