Gary Tyrrell, 60, and his wife Jan were found murdered in their Springfield, Missouri home after their daughter Jessica checked on them on May 1, 2014. Jan was discovered dead on the first floor and Gary in an upstairs bedroom. Investigators reported Gary had been beaten and shot twice; Jan died of blunt force trauma. There were no signs of forced entry, and while some valuables remained, a rare-coin collection belonging to Gary was missing and a safe had been tampered with.

The coins were valued at about $22,000.Trouble focused on Mark Porter, a 53-year-old former superintendent and friend who had recently asked Gary for a $250,000 loan. Porter sold more than $18,000 worth of silver coins days after the killings. A latex glove found near Jan’s body yielded DNA that matched Porter's sample taken from a discarded coffee cup. Porter was arrested, charged with first-degree murder, and later pleaded guilty to two counts of second-degree murder in a deal to avoid capital punishment; he received two consecutive life terms.

Does anyone with knowledge of the Tyrrells or their circle have additional information about the missing coin collection or contacts Porter may have used to sell them?