After a young teacher named Nicole VanderHeyden was found shot to death in a Wisconsin farm field, police arrested her live-in boyfriend who had waited 18 hours to report her missing. But his Fitbit device proved he was asleep at home the night of the murder, and a stranger VanderHeyden met at a heavy metal concert in a local bar became a prime suspect.  Learn more about your ad choices. Visit podcastchoices.com/adchoices