A military jury has began mulling its verdict in the trial of a US Army dog handler accused of abusing inmates at Iraq's Abu Ghraib prison.
Sgt Cardona is the second dog-handler charged over Abu Ghraib
The jury of seven must decide whether Sgt Santos Cardona, 32, was guilty of playing vicious games or was just following orders.
Sgt Cardona is accused of several charges including aggravated assault, for letting his dog harass detainees.
If convicted he faces up to 16 years behind bars.
The prosecution has described Sgt Cardona as one of a group of "corrupt cops" who tormented Iraqi prisoners for fun.
But the defence has argued that the accused was only obeying orders from senior officers.
Summing up the case, chief prosecutor Major Christopher Graveline showed the jury large photographs depicting naked prisoners cowering against a prison wall to escape the dogs.
Sgt Cardona had used his Belgian shepherd dog like "a weapon", Maj Graveline said, likening the bites on one of the prisoners' legs to bullet wounds.
"They were doing their own thing for their own entertainment," he charged.
"If this was an American soldier in the hands of some of our captors, would we consider that mistreatment?"
But civilian defence lawyer Harvey Volzer said his client had done "nothing wrong" and had acted only after facing extreme pressure from his superiors.
Describing the jail as "a zoo", Mr Volzer argued that the command structure was chaotic and that solders were not given clear instruction about how to use the dogs.
The five-day trial, held at Fort Meade military base outside Washington, began on 24 May.
Sgt Cardona is being tried on multiple charges, including assault, dereliction of duty, conspiracy to maltreat detainees and making a false statement to investigators.
He is also accused of taking part in a contest with another guard to see who could make the most prisoners urinate out of fear.
Last week, the prosecution related how guards at Abu Ghraib would shackle detainees and let dogs snarl and bark in their faces "for nothing more than the entertainment of corrupt cops serving on the night shift".
A total of 10 US soldiers have already been found guilty of abuses at Baghdad's Abu Ghraib prison.