The murder of Cortney Clayton

It was a Friday night in Stamford, Texas on September 2nd, 1988, and seven year old Cortney Clayton wanted to buy a soda from the convenience store less than a block away from her home. After begging her father, he gave her money and instructed her to wait for her brother, Ryan, outside of the store to cross the street. Cortney headed to the store at 8:42PM, and purchased a cup of soda at 8:47PM. Ryan left their home three minutes after her, and when he arrived outside the store at 8:50PM, he did not see Cortney waiting for him outside. After searching inside the store for her, the clerk told him that Cortney had paid for her soda and left. He then headed home, assuming Cortney had arrived back. Unfortunately, when Ryan returned home, Cortney was not there. After searching the nearby alley and neighborhood to no avail, Cortney's parents, Stan and Candace Clayton, reported her missing at 9:20PM. At the start of the search, investigators learned from witnesses that Cortney was seen at the convenience store and was last seen heading north at 8:48PM. Numerous sightings were called in, searches were conducted, and a witness who saw a man parked outside the convenience store was able to provide a detailed description that resulted in a composite sketch being distributed, but no progress was made. On March 26th, 1989, a hunter discovered a skull, which lead to the recovery of an arm, leg, and rib bones the next day. The remains were identified as Cortney Clayton. Almost four decades later, there has been no identification or arrest of Cortney Clayton's killer. Who killed her? Sources https://www.newspapers.com/image/764768420/?terms=Cortney%20Clayton&match=1 https://www.newspapers.com/image/764769390/?terms=Cortney%20Clayton&match=1 https://www.newspapers.com/image/299887118/?terms=Cortney%20Clayton&match=1 https://www.newspapers.com/image/764769603/?terms=Cortney%20Clayton&match=1 https://www.newspapers.com/image/431596044/?terms=Cortney%20Clayton&match=1 https://www.newspapers.com/image/299889440/?terms=Cortney%20Clayton&match=1 https://www.newspapers.com/image/764769762/?terms=Cortney%20Clayton&match=1 https://www.newspapers.com/image/640983282/?terms=Cortney%20Clayton&match=1 https://www.newspapers.com/image/764769888/?terms=Cortney%20Clayton&match=1 https://www.newspapers.com/image/640813313/?terms=Cortney%20Clayton&match=1 https://www.newspapers.com/image/764770572/?terms=Cortney%20Clayton&match=1 https://www.newspapers.com/image/764770776/?terms=Cortney%20Clayton&match=1 https://www.newspapers.com/image/764771632/?terms=Cortney%20Clayton&match=1 https://www.newspapers.com/image/611761310/?terms=Cortney%20Clayton&match=1 https://www.newspapers.com/image/764772466/?terms=Cortney%20Clayton&match=1 https://www.newspapers.com/image/640977069/?terms=Cortney%20Clayton&match=1 https://www.newspapers.com/image/640980555/?terms=cortney%20clayton&match=1 https://www.newspapers.com/image/589267513/?terms=cortney%20clayton&match=1 https://www.newspapers.com/image/640815694/?terms=cortney%20clayton&match=1 https://www.newspapers.com/image/300194446/?terms=cortney%20clayton&match=1 https://www.newspapers.com/image/764763627/?terms=cortney%20clayton&match=1 https://www.newspapers.com/image/764764086/?terms=cortney%20clayton&match=1 https://www.newspapers.com/image/777901879/?terms=cortney%20clayton&match=1 https://www.newspapers.com/image/764765924/?terms=cortney%20clayton&match=1 https://www.newspapers.com/image/764601389/?terms=cortney%20clayton&match=1 https://www.newspapers.com/image/640824062/?terms=cortney%20clayton&match=1 https://www.newspapers.com/image/764604633/?terms=cortney%20clayton&match=1 https://www.newspapers.com/image/640976802/?terms=cortney%20clayton&match=1 https://www.newspapers.com/image/431612913/?terms=cortney%20clayton&match=1 https://www.newspapers.com/image/764754990/?terms=cortney%20clayton&match=1 https://www.newspapers.com/image/764755811/?te