A United States judge has declared a mistrial in the sexual assault trial of celebrity comedian Bill Cosby after jurors could not reach a unanimous decision about Cosby’s guilt.

The jury deadlocked after more than 50 hours of deliberation in Norristown, Pennsylvania, over charges that he drugged and then molested a woman in 2004.

WATCH: Cosby defense team on jurors

Prosecutors said immediately that they would retry the Cosby Show star, and he remains charged with three counts of aggravated indecent assault.

The jury seemed exasperated at times over the course of the week as it repeatedly asked the judge for clarifications of evidence or to hear testimony from the trial again.

Jury couldn’t reach unanimous decision

On Thursday, the fourth day of deliberation, jurors told Judge Steven O’Neill they were deadlocked, but he instructed them to keep working to try and reach a unanimous decision.

On Saturday, after they reported to O’Neill they were at an impasse and would not be able to reach a consensus, he was forced to call a mistrial.

​The 79-year-old Cosby is charged with drugging and assaulting Andrea Constand, a former director of operations of the Temple University women’s basketball team.

He allegedly gave her pills that paralyzed her and left her unable to resist when he started touching her in his Philadelphia home.

Faced life in prison

If found guilty, Cosby could go to prison for the rest of his life.

More than 50 women claim Cosby sexually assaulted them in incidents dating back to the 1960s, when he emerged as a major comedy star. Most of the alleged incidents occurred too long ago to be prosecuted now.

Constand’s complaint is the only one that has come to trial. Cosby has denied all the charges.

WATCH: Prosecutors say they’ll retry case
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