
An in-depth look at the terrifying offenders whose crimes earned them rare life sentences; despite being imprisoned, these inmates go on to torture, kidnap and even kill.

One of the UK's most infamous serial killers, Joanna Dennehy brutally stabbed three men to death.

James Robertson is one of the most feared men in the US prison system; he murdered his cellmate, attacked a prison employee and doesn't hold back from getting what he wants.

Covered in tattoos, his terrifying appearance makes Jaime Osuna a feared man in the U.S. prison system; awaiting trial, he begins practicing Satanism and attempts to kill a fellow inmate.

While on trial for rape, 33-year-old Brian Nichols goes on a violent rampage that results in three murders.