I had a very serious stalker except mine was more intelligent and more moneyed than this emotional wreck, it was a real problem and based on a sort of one night stand that turned into a few days or week and then what I thought was an accidental meeting at a bar/restaurant 3 years later, which is when the nightmare started.
So did my neighbor and it was an ex girlfriend. She tormented him for a year before he finally had enough and killed her.
They worked at the same plant and he walked into work one day and shot her dead.