Mr Brancato says he was a bystander in the murder.
Sopranos actor Lillo Brancato has been cleared of second degree murder over the shooting of an off-duty police officer in 2005.
The 32-year-old former star of the hit US TV series was convicted of attempted burglary by a jury in New York. He faces a minimum of three years in jail.
Brancato and an accomplice were accused of breaking into an apartment in the city to steal prescription drugs.
Officer Daniel Enchautegui, who lived next door, was shot in the incident.
Correspondents say Brancato - who played Matt Bevilaqua in the drama's second series - may be released early because of time already served. He is due to be sentenced next month.
When giving evidence at the murder trial Brancato said he did not know his accomplice, Steven Armento - his ex-girlfriend's father - was armed when they went looking for drugs.
He added that he was suffering heroin withdrawal at the time. "I was dope sick. Mentally, I was a mess. I needed something," he told the jury.
Armento was convicted of first-degree murder in October and sentenced to life in prison without parole.