Late last week, a 12-person jury spent 14 hours deliberating the fate of a New Orleans teenager accused of murdering an illegal immigrant two years ago in Slidell during a botched robbery.

In the dark, vacant hallways of the courthouse, long after the rest of the court house had gone home, Defense attorney Martin Regan told Glenn Carter’s family that the long deliberation — one of the longest bailiffs and clerk courts said they’ve experienced — was a good sign. It meant 10 of the 12 jurors needed to convict Carter of second-degree murder struggled on whether to send the teenager to life in prison.

He was wrong. Carter was convicted early Saturday, about 2 a.m. of second-degree murder in the April 29, 2007 killing of Salvadorian immigrant Carlos Luis Martinez-Carpio, 36. Following in his steps Monday, Carter’s former classmate at Slidell High School and accused accomplice Edric Cooper pleaded guilty to manslaughter, a crime made in the “heat of passion.”

“When he saw (Carter) was guilty as charged, he saw the writing on the wall,” District Attorney Walter Reed spokesman Rick Wood said. “He offered a plea.”

Cooper, originally charged with second-degree murder punishable by mandatory life in prison at hard labor without the possibility of parole, faces up to 40 years in prison for the manslaughter conviction. State Judge William Burras set a sentencing date Sept. 12, Rick Wood, District Attorney Walter Reed spokesman said.

While Carter was the one accused of pulling the trigger during the robbery, Cooper is charged of being the mastermind behind the plot to rob Martinez-Carpio and six other illegal immigrants. Two other accomplices Grant Gethers, 19, of New Orleans and Jace Washington, 20, of Slidell, also face upcoming trials for the murder.

Prosecutors offered Carter’s tape confession during his five-day trial last week that Regan hinted was cohered after more than 27 hours of questioning during which time Carter urinated on himself because he wasn’t allowed to use the bathroom, Regan said. The first confession was about 3 a.m. May 4 and another 12 hours later at 3 p.m. later that day. The defense never confirmed the allegations and called no witnesses to the stand.

The majority of Carter’s defense rested on Regan cross-examining prosecutions witnesses. During closing arguments Regan pleaded for sympathy for the teenager.

Sheriff’s Office deputies at the time said Carter and Washington stormed the trailer at 35591 Madison St. around 9 p.m. and stumbled upon Martinez-Carpio cooking dinner.

Cooper and Gethers waited outside, serving as lookouts in a getaway car.

While Martinez-Carpio’s roommates from El Salvador, Mexico and Honduras sat in a back room eating, Martinez Carpio found himself alone cooking dinner, authorities said. He armed himself with a fork and tried to stab Carter.

Then shots rang out.

“The gun just went off,” Carter said on the tape. “It all just happened so fast.”

Cooper had launched the robbery plot to get some “fast money,” by robbing the trailer a few blocks from his home, Carter said on the tape.