By definition, a serial killer is a person who murders three or more victims in a relatively short period of time for the sake of personal gratification. All the people on this list have been dubbed serial killers because they not only fit this description, but they've also shown no remorse once they were caught by the authorities!

These men come from different backgrounds, but the one thing that binds them is their lust for human suffering, pain and blood. Here are the world's deadliest serial killers.

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