World's Most Evil Prisoners

Sent to prison after the torture and violent murder of a mother of six, Jamie Osuna is now awaiting trial.

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

At 18, Christa Pike commits a brutal murder and becomes one of the youngest ever women sent to death row.

Edward Johnson is sent to prison for the brutal murder of a female friend, but the violence doesn't end there.

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

Being behind bars only made Italian-American mobster Freddy Geas even more brutal.

James Robertson is considered one of the most volatile, dangerous men in the U.S. prison system.

Gary Vinter, in prison for double murder, stabs a fellow inmate in the eye and gives another brain damage.

James 'Porky' O'Rourke's addiction to violence means he is one of the most feared men in the UK prison system.