A prosecutor at the murder trial of Lillo Brancato Jr. told jurors Monday the former "Sopranos" actor got involved in the killing of an off-duty police officer during a desperate mission to steal drugs.

But the defense said Monday in opening statements that the only culprit was the man already convicted in the shooting.

Brancato, 32, is charged with second-degree murder in the 2005 death of Officer Daniel Enchautegui.

Both sides agreed he had a severe drug problem.

Assistant District Attorney Theresa Gottlieb said Brancato and the other man, Steven Armento, had set out to steal prescription drugs.

Brancato's attorney, Joseph Tacopina, said the only culprit was Armento, who was convicted of first-degree murder on Oct. 30 and has been sentenced to life in prison without parole.

Authorities say the pair broke into an apartment to steal drugs after a night of drinking at a strip club. Enchautegui, who lived next door, came out to investigate and Armento shot the 28-year-old officer in the heart. Enchautegui fired back, wounding both men.

"Lillo was there to satisfy his addiction. But he wasn't there to do violence — and that's important," Tacopina said in his opening statement.

Tacopina denied that his client ever entered the apartment, and said Brancato did not know Armento had a gun.

Brancato made his debut in 1993 in "A Bronx Tale" opposite Robert De Niro. He's appeared in more than a dozen other movies and played a doomed aspiring mobster in HBO's "The Sopranos."