An appeals court overturned Wednesday the death sentence of the convicted killer of two undercover New York police officers, saying prosecutors unfairly tried to influence the jury in the case.

The federal Court of Appeals in New York upheld Ronell Wilson's conviction for the 2003 murders but said the death sentence -- the only one pending in the state -- must be reviewed.

The appeals court said it voided the death sentence "because two arguments made to the jury by the prosecution -- both bearing on the critical issues of remorse, acceptance of responsibility and future dangerousness -- impaired Wilson's constitutional rights."

According to the court, the prosecution unfairly argued that Wilson's claims of remorse should be discredited because he declined to plead guilty and refused to testify in his trial.

The court said a defendant's rights are "violated when failure to plead guilty is treated as an aggravating circumstance."

Robert Nardoza, spokesman for the US attorney's office for the Eastern District of New York, said "we are reviewing the decision and considering our options."

New York reinstated the death penalty in 1995 but it was ruled unconstitutional in 2004.