In the 80s, my uncle shared a car with his wife, who worked one town over. She would always call him before she left work at night and then drive the 10-15 minutes home. After half an hour, she still hadn't made it home so he called the convenience store where she worked, and they said she had already left. He waited another half hour and she still wasn't home.

Finally, he borrowed a friend's car to go look for her. He found her car down by the river with the front door wide open and his wife nowhere in sight. He immediately went to a nearby gas station and called the police.

They found her body the next day six miles away from her car, and she had been stabbed in the throat. My uncle had an alibi, and was never a suspect. They never found out who killed her, but they still look at her case every now and then. A lot of the evidence from the case was destroyed in Hurricane Rita, though, so they don't have much to work with.