CBS (CHICAGO)–Drew Peterson has filed an appeal with the U.S. Supreme Court to reconsider hearsay evidence in a murder conviction upheld last year by the Illinois Supreme Court.

In the appeal filed Monday, the former Bolingbrook Police Officer, convicted of drowning his third wife,  challenged that unanimous 2017 high court decision.

In that ruling, Justices decided hearsay testimony from Kathleen Savio, Peterson’s third wife, as well as his missing fourth wife—Stacy Peterson—did not violate his constitutional rights because of evidence Peterson killed them to prevent their testimony.

The 63-year-old is serving a 38-year prison sentence for Savio’s 2004 murder. He also has a 40-year consecutive sentence for being convicted of plotting to kill Will County State’s Attorney James Glasgow.

The appeal does not mean Peterson’s case will be heard by the Supreme Court. At least four Justices would need to agree to take the case.

About 7,000-8,000 new cases are filed in with the Supreme Court each year.

The court hears oral arguments from attorneys in only about 80 of those cases each term, and approximately 100 are discarded before reaching that point, according to the U.S. Supreme Court website.