Gary and Jan Tyrrell of Springfield, Missouri were collectors. They kept lots of their rare, valuable collections in their home. When they were found dead in that home on May 1, 2014, police were surprised to see that there was no forced entry and that most of the valuables remained intact. Investigators suspected the Tyrrells’ longtime friend Mark Porter who had “gambling issues.” Although he reportedly made $275,000 year from his job at IBM, Porter owed $250,000 in gambling debts. Porter asked the Tyrrells for a loan but they refused.
During the double homicide investigation police found DNA on a latex glove found in the house. They asked Porter for a DNA sample but he refused. Savvy detectives followed Porter to a “quick lube” shop, where Porter left behind a coffee cup. The detectives picked it up and the DNA matched. That wasn’t all the evidence they found. One day after the Tyrrells were discovered dead in their home, Porter sold $18,000 worth of silver coins to a local shop. Porter pleaded guilty to both murders and is serving two consecutive life sentences. Dateline NBC will air its investigative report about “The Collector” on February 21 at 7pm.