The chaotic evil alignment was power without control, selfishness unrestrained by law and order. Chaotic evil characters acted according to whatever their greed, hatred, and lust for destruction drove them to do. Whether out for themselves, or dedicated to a cause that spread evil and chaos, they were ruthless and brutal in their execution.
Typically, they could only be made to align and work with others through force or coercion, with leaders lasting only as long as they could thwart attempts at being overthrown or assassinated. Ultimately, these characters will commit any act to further their own ends.
Many serial killers would fit this description, as would indeed most of the more violent and reckless criminals found in the worst sorts of places.