Per award-winning author and former law enforcement officer, Micki Browning, the villain's motivation is the first thing a fiction writer should nail down when outlining or drafting their crime story. It is the motive and the mindset of the person that commits a crime that captivates readers and drives the story forward. The story can differ greatly, Browning says, depending on what that motivation is - whether it's revenge, love, money, or something else. Other factors to consider when creating a villain include giving your villain redeeming qualities or relatable attributes. Readers will quickly lose interest in a cookie cutter villain. Even the most legendary villains, such as Hannibal Lecter, have likable traits.
I love it when a villain makes a reader conflict between knowing he's a bad guy and then rooting for him, makes it so interesting and you can see it from both sides.