This security expert did, and boy it was a whopper. 
Security expert Michiel Oakes admitted killing Mark Stover. Oakes said that Stover was stalking his girlfriend and she was very afraid of Stover. This girlfriend, Linda Opdycke, was Stover’s ex-wife.  Oakes said he did it in self-defense. The jury wasn’t convinced, and convicted Oakes of first-degree premeditated murder.
For more backstory see this article on NPR, and this from The Seattle Times.
For those of you who may be stalked in the future, here are 3 mistakes to avoid:
No Documentation. According to this story, Oakes never reported any threats by Stover to the police. If you believe you’re being stalked, get an evidence trail going, including what you’ve reported to police. A history that others can refer to really helps your believability. And maybe you can get some help!
Going to Stalker’s Home, Armed. If you go to your stalker’s house wearing a bulletproof vest and carrying weapons, it will be hard to convince anyone except your mother that you acted in self-defense. (In fact, if I did that, my mother would probably be the first to turn me in for stupidity.)
And Then Hiding the Body. Nothing screams guilt like a cover-up (whether or not that’s accurate). Really, this is the stuff of bad TV and movies. 
Stalking is serious.  I’ve had students in my self-defense classes who’ve been stalked, and even years later many have never regained their full peace of mind. If you are being stalked, or someone you know is being stalked, do report and report and report, keep documents and a diary and any phone messages, and let everyone in your circle know. Before you end up, losing, on center stage in a bad drama.