NEW YORK (AP) – A young man convicted of shooting two detectives in the head during an undercover gun buy – one as he begged for his life – was sentenced Tuesday to death at a federal penalty trial.

A Brooklyn jury had deliberated since Monday before sentencing Ronell Wilson to die by injection. The jury had convicted Wilson last month of two counts of murder, along with robbery, carjacking and firearms charges.

Wilson, 24, becomes the first person in more than 50 years to be sentenced to death in a federal case in New York. The last time was in 1954 for a bank robber who killed an FBI agent.

Prosecutors claimed the defendant knew that Rodney Andrews and James Nemorin were undercover New York Police Department detectives when he climbed into the back seat of their unmarked car on the pretense of selling them an illegal gun on Staten Island in 2003. Both officers took bullets to the head, Nemorin after he pleaded for his life.

Wilson “slaughtered two innocent men, taking from them everything they were and everything they would be,” Assistant U.S. Attorney Jack Smith said in closing arguments Monday at the trial’s penalty phase.

An accomplice testified that he and Wilson were in on a plot by a violent drug gang to rob the undercover detectives, believing they were carrying $1,200 to buy guns. But the defense contended there was no convincing evidence the men knew their victims were police officers.

Wilson’s attorney, Kelley Sharkey, had cautioned jurors they were making “the ultimate moral decision,” and she urged them to show mercy.

“You must be able to say to yourself that 24-year-old Ronell Wilson is beyond hope, is beyond redemption,” she said.

Prosecutors made the case for execution by presenting emotional testimony by the detectives’ widows about their devastated families. Entered into evidence was the last photo ever taken of Andrews, wearing a leather jacket and posing with his children at a wrestling match at Madison Square Garden.

At closing arguments, prosecutors displayed the jacket, still caked with dried blood from the night he was shot. They also cited a rap lyric authorities say Wilson scratched out after the shootings: “I ain’t gonna stop until I’m dead.”

Any verdict “should speak to the cold reality that Rodney Andrews and James Nemorin – two of the good guys – are no more,” Smith had said.

The defense countered with anecdotal evidence of Wilson’s troubled background as the mentally challenged son of a crack-addicted mother living with a dozen relatives crammed into an apartment at a crime-infested housing project.

“His early years were filled with drugs and chaos,” Ms. Sharkey said Monday.

The same Brooklyn courthouse has been the venue for an unprecedented three simultaneous death penalty trials – Wilson’s and those of a notorious druglord and a gang member accused of shooting a man in the head to pay off a debt to a cocaine supplier.

Jurors were still deliberating in the druglord’s case. Another jury convicted the gang member but spared his life when it failed to reach a unanimous verdict on a death sentence.

There are fewer than 50 inmates nationwide on the federal death row. Three, including Oklahoma City bomber Timothy McVeigh, have been put to death since 2001.

Wilson was one of seven people arrested in his case; the other six pleaded guilty to various charges.