The U.S. Supreme Court ruled on Monday that Los Angeles County's former top prosecutor and his deputy cannot be sued by a man wrongly imprisoned for 24 years based on a jailhouse informant's false testimony.

The high court unanimously ruled that supervisory prosecutors are entitled to immunity from civil rights lawsuits that seek damages for the failure to develop proper policies to share information about informants.

The decision was a defeat for Thomas Goldstein, who had been convicted of a 1979 murder in Long Beach, California, on the strength of a jailhouse informant's testimony that he had confessed to the crime.

The informant testified in court that he received no benefit in return for his testimony, but evidence later emerged that he had struck a deal to get a lighter sentence.

A federal appeals court ruled that Goldstein had been wrongly convicted. He was released from prison in 2004.

Goldstein then sued former District Attorney John Van de Kamp and his former chief deputy, claiming that as supervisors they had a policy that relied on jailhouse informants even though it sometimes resulted in false evidence.

The Supreme Court held in 1976 that prosecutors acting as part of their official duties have immunity, but the ruling in Goldstein's case made clear immunity also extended to supervisory prosecutors and their managerial duties.

Justice Stephen Breyer wrote in the opinion that immunity covered claims about a failure to train or supervise prosecutors or to set up an information system with material that calls into question the truthfulness of informants.

Breyer said allowing the lawsuit to go forward would permit criminal defendants to bring claims for other trial-related training or supervisory failings, affecting the way in which prosecutors carried out their basic courtroom tasks.

In another decision involving criminal defendants, the court unanimously ruled that officers may frisk a passenger of a vehicle lawfully stopped for a traffic violation as long as they reasonably suspect the person is armed and dangerous.

Justice Ruth Bader Ginsburg said in the opinion that an Arizona court was wrong to rule that the police could pat down an armed and dangerous passenger in a vehicle only if they believed the suspect had been involved in criminal activity.