Ira Einhorn

Ira Samuel Einhorn (May 15, 1940 – April 3, 2020), known as "The Unicorn Killer", was an American convicted of murdering his ex-girlfriend, Holly Maddux. He was born in Philadelphia, Pennsylvania.
On September 9, 1977, Maddux disappeared following a trip to collect her belongings from the apartment she and Einhorn had shared in Philadelphia, Pennsylvania. Eighteen months later, police found her partially mummified body in a trunk in Einhorn's closet.
After his arrest, Einhorn fled the country and spent twenty-three years in Europe before being taken back to the United States. He said that his ex-girlfriend had been killed by CIA agents who framed him for the crime because he knew too much about the agency's paranormal military research. 
He was convicted and served a life sentence at a prison in Pennsylvania until his death in prison in April 2020 of heart disease, aged 79.