Sgt. Javal Davis (search) said he hopes that admitting his abuse of Iraqi detainees at the Abu Ghraib (search) prison can somehow save his Army career.

Davis pleaded with jurors Thursday to show him mercy, saying he made a mistake by indulging in a few minutes of poor judgment.

"I'm not a perfect soldier — I'm not G.I. Joe," Davis said. "I don't want to see (my career) go down the drain for some foolishness."

He apologized to the jury of four officers and five senior enlisted men.

"I'm embarrassed and ashamed that I embarrassed the country and the Army that I love," he said. "I don't know what I was thinking that night. I should not have done that."

In a deal with prosecutors, Davis, 27, a reservist from Roselle, N.J., pleaded guilty earlier this week to battery, dereliction of duty and lying to Army investigators.

His sentencing hearing was expected to wrap up Friday.

Davis has confessed to stepping on the hands and feet of detainees and then falling with his full weight on them. Davis, who is about 6-feet-1 and weighs nearly 220 pounds, has blamed his crimes on job-related stress.

He faces a maximum 61/2 years in prison, but defense lawyer Paul Bergrin has said the plea deal caps Davis' sentence at 18 months.

The jury's sentence recommendation will be compared to the deal offered to Davis, and the lesser sentence will be imposed.

Davis described harsh conditions for the Abu Ghraib guards, saying they had to sleep in filthy jail cells and eat bad food while working long hours trying to control vast numbers of hostile prisoners.

"Abu Ghraib was like hell on earth," he said.

A psychology professor testified that Davis' abuse of detainees was triggered by the violent atmosphere at the prison and a lack of military discipline among guards.

Ervin Staub, who teaches at the University of Massachusetts, said Davis' abusive behavior as a prison guard followed a common pattern in which ordinary people become more physically aggressive in a brutish and unrestrained environment.

"Rules didn't exist," Staub testified. "There was a lawlessness that developed."

But prosecutor Capt. Chris Graveline referred to other alleged incidents involving Davis, including a threat to an Air Force major and an assault on an Iraqi citizen. He said Davis sexually taunted prisoners and once counted out bullets and told detainees he had one for each of them.