Mary Kathleen Rodriguez (5 of Spades, Texas)

For more than three decades, the question of who killed 26-year-old Mary Kathleen Rodriguez has hung over the town of West Odessa, Texas. Known as Kathleen to those who loved her, the live-in nanny was found brutally beaten to death inside the home of the couple she worked for. Although the case has changed hands from one detective to another, the original facts of the case remain the same. There was no sign of forced entry, meaning Kathleen almost certainly knew whoever came to the door that night. And the one person who could have been on the other side of that door is still at large.