QuasiMondo

There are various degrees of murder based on circumstance and intent. You can set out to kill a person. You can have a severe emotional reaction and lash out and take it too far. You can display gross negligence that causes a person's death. There are ways of intentionally and unintentionally killing somebody.

When you steal an item, you can't do it unintentionally. If you've held a job as a security officer for a store I'm sure you've heard the excuse, "I forgot to pay for it," from a shoplifter at least one time, and I'm sure that excuse didn't fly.

Killing a person isn't always driven by intent. It can be fueled by blind emotion, or unintentional consequences. Stealing, on the other hand requires intent. When you steal something, it's already in your mind, "I'm going to take it."

Debatable point: If you have a passenger in their car, and they leave their iPod in your car by accident, when they discover you have that iPod, does that make you a thief since it's in your posession unintentionally?

__________________
Cameron originally envisioned the Terminator as a small, unremarkable man, giving it the ability to blend in more easily. As a result, his first choice for the part was Lance Henriksen. O. J. Simpson was on the shortlist but Cameron did not think that such a nice guy could be a ruthless killer.

-From the Collector's Edition DVD of The Terminator