Arlene and Seymour Tankleff (retired insurance banker) lived in Belle Terre, Long Island with their adopted child, Marty Tankleff.
Marty called 911 on September 7, 1988 at 6:11am. He told the operator his father was still alive bust gushing blood from his neck while his mother was already dead in the master bedroom.
When police arrived at the scene, Arlene Tankleff was found dead. However, her husband did survive for 29 days in a coma but died shortly after.
Marty Tankleff was first on the suspect list. He was arrested after being questioned for a few hours.