Those who have chosen to uphold the law don’t always succeed in bringing criminals to justice, and sometimes they fail so spectacularly that the criminals slip right through their fingers, leaving people to wonder how they could have escaped so easily:
There are 21 Terrifying Criminals Who Are Still On The Loose according to this Cracked user submission compilation, 21 nefarious no-goodniks who managed to avoid prosecution for their crimes, and for most of them that's where the terrifying part ends:
Don't get me wrong, there are many bad guys on the list who deserve to be called "terrifying", but they're lumped in with thieves, hackers, and fixers of baseball games who hardly live up to the terror title.
However, there are enough true crime tales in this collection to pique the interest of the avid armchair criminologist, despite the somewhat clickbaity title, and you won't believe how easy it is for some people to dodge the long arm of the law!
(May contain language which is NSFW)