WIESBADEN, Germany (AP) _ A U.S. Army soldier who confessed to killing a fellow serviceman after a night of drinking was convicted Friday of murder and robbery and sentenced to life in prison with the possibility of parole.

Pfc. Jonathan Schroeder told a U.S. military court that he and Pfc. Andrew Humiston beat and robbed Pfc. Clint C. Lamebear after finding him drunk in a bar in the city of Frankfurt.

Schroeder told judge Col. James Pohl he had no excuse for his actions.

``What started as a joke, just to teach him a lesson _ don't go out and get too drunk _ escalated to his death, sir,'' he said.

Schroeder, 21, of Oxford, Miss., pleaded guilty to charges of felony murder, robbery, conspiracy to commit robbery and obstruction of justice. The maximum sentence was life without parole.

Humiston, of Champlin, Minn., faces the same charges and a maximum sentence of life in prison without parole. His court martial was to begin Tuesday.

During a detailed grilling by the judge, Schroeder recounted how he and Humiston found Lamebear slumped in a bar on November 2001 and set out to bring him back to their base in nearby Friedburg.

Lamebear, 18, had arrived four days earlier to join the 1 Armored Division's 1st Battalion, 36th Infantry Regiment, 1st Brigade.

The two soldiers decided to ``teach him a lesson'' and rob him on the way home, Schroeder testified. They took Lamebear into a garage and Schroeder hit him, then held him in a headlock, while Humiston pulled his wallet from his pocket and found $40, Schroeder testified.

When Lamebear began to shout in protest, Schroeder panicked.

``I saw some boards, so I grabbed one to knock him out,'' he testified.

After hitting Lamebear with the lumber, he stole his watch and fled with Humiston. As they were leaving, Schroeder testified he checked Lamebear's pulse and he still had one.

After more drinking at a local bar, Schroeder returned twice to check Lamebear's pulse. The first time he had one, the second time he did not.

``I didn't want him to be dead,'' said Schroeder, who has been in pretrial confinement with Humiston at Coleman Barracks in Mannheim since November.

Lamebear's mother, Kristin June, choked back tears, as she told the court that her son was the one out of her three children whom she knew she could always count on to stand by her in tough times.

``I knew he would always be there for me,'' June said.

She told the judge she didn't want her son to go into the military, because it would take him too far away from her. But as the descendant of two Navajo code talkers _ one of whom received a Medal of Honor for helping develop the secret World War II code _ Lamebear already knew by high school that he wanted to spend his life serving his country.

In a final statement, Schroeder looked at Lamebear's mother, stepfather and cousin who were sitting in the courtroom.

``I have spent the past seven months trying to think of what I could say to you that would make it better,'' he told them. ``I have no words to express how I feel. I'm sorry.''