Morbid Thoughts by Michael McGovern

Aaron Walsh is a psychopath. For years he has kept that fact hidden, but one bad day is about to bring it all out into the open. When Jane Flannery walks into his computer repair store, he becomes obsessed. He wants to know every detail about her life. Unfortunately for Jane, Aaron has everything he needs. Her computer. Jane is in great danger and she doesn't even know it yet.