PHILADELPHIA (AP) — Bill Cosby‘s lawyers have asked the state Supreme Court for another chance to have his criminal sexual-assault case thrown out.

The defense argued that the current district attorney cannot go back on the word of a predecessor who has said he promised Cosby wouldn’t be charged in the case. The defense said Cosby relied on that pledge when he testified in a related lawsuit about his contact with the accuser and other women who have accused him of drugging and molesting them.

“When a district attorney acts for the Commonwealth and assures a criminal defendant that he will never be prosecuted for a particular event, that promise must be enforced,” the lawyers wrote in a brief posted Friday on the court’s website. “And it certainly must be enforced where, as here, the defendant detrimentally relies on that assurance in waiving constitutional rights, including his right against self-incrimination.”

Cosby, 78, was arrested last year after his deposition in the decade-old case became public and Montgomery County prosecutors reopened the case. He is charged with felony sexual assault over his 2004 encounter with a former Temple University employee.

He has been free on $1 million bail since his arrest in December.

He has a May 24 preliminary hearing scheduled unless the Supreme Court grants his appeal. A county judge and the state’s Superior Court have previously rejected the defense arguments.

Cosby has not entered a plea in the case but said in the deposition that the encounter was consensual. Lawyers for the accuser say she was drugged and could not give consent.

Cosby, who played Dr. Cliff Huxtable on “The Cosby Show” from 1984 to 1992 and has been married for decades, has denied the other women’s accusations. The statute of limitations has expired in most of the cases against him.