World's Most Evil Prisoners

Craig Bjork, who killed two women and both of his children, remains a dangerous threat -even behind bars.

Whilst being transported on a bus, Ricky Dubose killed two correctional officers before going on the run.

After cold-blooded killer Leo Boatman murdered two campers, he went on the kill three inmates behind bars.

Jesse Con-ui's loyalty to the New Mexican Mafia drove him to betray and murder his former mentor.

Thomas Silverstein, a killer and gang leader, was so dangerous that he spent 36 years in solitary confinement.

Having committed over 27 assaults in prison, Billy Tracy is one of the most violent offenders on death row.

Career criminal Michael Dutcher has continued his streak of violence and murder even behind bars.

Imprisoned for murdering a woman and her teenaged son, Denver Simmons only caused more violence behind bars.

Remorseless murderer Casey Pigge's main ambition is to be the ultimate serial killer.

Feared Aryan Warriors gang leader 'Mugsy' Williams was a one-man crime wave - even behind bars.