Our card this week is Thomas Mather, the seven of diamonds from Iowa.

Nothing causes the true crime community to stir more than a case with an open-ended question

of did he or didn't he? Well, except that is when the question is, did she? For longer than 32-year-old Thomas

Mather was alive, a rural town in Iowa has been haunted by its only unsolved homicide. The former

sheriff told us it's the only whodunit they have left. Does no foreign DNA evidence and strange behavior mean that Dawn Mather had to have been

involved in killing her husband?

Or does an unidentified fingerprint and tire tracks prove she didn't?

I'm Ashley Flowers, and this is the deck.

Music I'm Ashley Flowers, and this is the deck. The Sunset in Springdale, Iowa at 6.53 p.m. on September 30th, 1991. So by 8 p.m., it was pitch black outside of Mark Raymond and Mary Buckley's rural home when they heard a noise at their back door. Now, when the couple opened the door, they were shocked to see a naked woman in front of them.

24-year-old Dawn Mather, their neighbor, who lived just down the way. Now, before they had a chance to ask Dawn what was happening, she told them, there's a man in our house that has a gun. Mark and Mary

immediately took Don inside, locked the doors, covered Don with a robe, and called for help.

While EMTs and even a few of Don's friends rushed to where Don was, law enforcement was sent to the Mather House.

Sheriff's deputies were worried that the farmhouse, close to 100 yards away, might still shelter the gunmen with Dawn's husband,

32-year-old Tom Mather.

Now-retired deputy Dale Edens was one of the first people to arrive.

He immediately got on his loudspeaker and ordered everyone outside.

There was no movement from inside the house.

The deputies had a dispatcher try calling the landline inside,

and they could hear it ring and ring.

And when no one answered, they decided it was time to go in.

When backup arrived, they approached the front door,

and Deputy Eden's could see that it had been left wide open,

...