Tankleff was convicted of killing his parents, Seymour and Arlene Tankleff, on June 28, 1990, and sentenced to two consecutive terms of 25 years to life in prison. In December 1993, a divided
New York Supreme Court, Appellate Division affirmed Tankleff's conviction.{{cite court |litigants=People v. Tankleff Tankleff was admitted to the New York State Department of Correctional Services in October 1990. In state custody, Tankleff was incarcerated at the
Clinton Correctional Facility in Dannemora, New York, in a special housing unit called "APPU" for high-profile inmates and inmates at high risk of victimization. In January 1997, federal district Judge
Thomas Collier Platt Jr. denied Tankleff's petition for a writ of
habeas corpus.{{cite court |litigants=Tankleff v. Senkowski In an appeal 12 years later, his lawyers presented new evidence and witnesses. ==Appeals and exoneration==