A Marine lance corporal was sentenced Thursday to a year and nine months in prison for his role in the abduction and slaying of an Iraqi civilian in Hamdania last spring.

Lance Cpl. Tyler A. Jackson, the second member of his squad to be sentenced to prison this week, had pleaded guilty to reduced charges in a pretrial agreement with prosecutors.

Military judge Lt. Col. Joseph Lisiecki issued a sentence of nine years of confinement, but under rules of the proceeding the actual sentence was determined by the pretrial agreement. The 21 months includes six months already served.

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In a deal with prosecutors, Jackson last week pleaded guilty to aggravated assault and conspiracy to obstruct justice. Other charges including murder and kidnapping were dropped, and Jackson was required to testify about the incident.

Before the sentence was handed down, the prosecutor said in closing arguments that the squad, seven Marines and a sailor, had become a lawless gang intent on killing.

"They were not a squad of Marines; they were a gang with a state of mind to kill someone," Maj. Donald Plowman said.

Defense attorney Lt. Col. Paul Starita said his client was a law-abiding Marine led astray by the poor leadership of the squad sergeant, who has been accused of hatching the plan to kidnap and kill an Iraqi man.

Jackson said his squad agreed to a plan to kidnap and kill Saleh Gowad, a man they suspected to be an insurgent. It was not until weeks after the incident, Jackson said, that he learned the man who had been killed was 52-year-old Hashim Ibrahim Awad, who prosecutors say was a disabled father of 11 and a former police officer.

"I wish I had the courage to prevent his death," Jackson said. He acknowledged that even if the man shot had been a known insurgent, kidnapping and killing him was not within the rules of engagement. "I feel sorry for what happened and I wish there was a way I could change it, but I can't."

But Plowman said that before Awad was dead, Jackson had plenty of time to reflect on the upcoming killing.

According to the prosecutor, Jackson sat for several hours with Pfc. John J. Jodka III and "casually discussed" the book "The Da Vinci Code" while waiting for squad mates to capture and return with the suspected insurgent.

"That suggests indifference," Plowman said, as he played a slideshow to the military judge featuring photographs of Awad's bullet-riddled body. "Someone was going to die that night."

Jodka, who pleaded guilty to similar charges, learned Wednesday he will serve a year and six months under terms of his plea deal rather than the five years recommended by the judge.

The corpsman, Petty Officer 3rd Class Melson J. Bacos, was sentenced to 10 years in prison but will only serve one.

Jackson said squad leader Sgt. Lawrence Hutchins hatched the plan to kill Gowad. Hutchins' attorney has said his client did nothing wrong in Awad's death.

The troops were frustrated because they knew Gowad was an insurgent who was responsible for planting a bomb that killed four Marines from a different unit, yet when they arrested him he was released by Iraqi authorities, Jackson said.

"It was kind of frustrating, it makes you believe that what you are doing over there doesn't have so much meaning," Jackson said. "If that's the No. 1 person and they release him, that diminishes what you think about the mission."

Three Marines and the Navy corpsman have made plea deals. The remaining four still facing kidnapping and murder charges are the more senior of the squad. Two more Marines are due in court next week.