>> there had to be more than one person involved in this. you couldn't leave a vehicle along the interstate and walk back to wherever you left from. someone had to drive there and pick you up and take you back. >> so, who would have had the motive and the opportunity to commit this crime? karyn's ex-husband, michael, had an alibi for the night of the murder, but his parents did not. they were the ones watching karyn's son, christopher, on the day of the murder. >> michael slover sr., he works at a power plant in the decatur area. once he clocked out, he has no alibi after that time. jeannette slover, who wasn't employed or anything, she had no alibi or anybody to corroborate their alibi. >> 51-year-old jeannette slover