Defense lawyers said the shooting episode appeared to be an inappropriate escalation of force amid a period of increasing desperation in the prison camps. Some detainees are becoming dangerously undernourished as they shun many meals, if not outright fasting.

“It’s hard to imagine there would be a realistic threat. They’re all detained, depressed and defenseless,” said attorney Baher Azmy at the Center for Constitutional Rights, the New York legal firm that coordinates the unlawful detention suits of Guantánamo detainees.

The incident occurred in one of the least likely places in the camps. Camp 6 is the detention center’s showcase prison for cooperative captives, where the military said last year it spent $744,000 in a soccer field with special access for detainees and air-conditioned guard towers to diminish contact and friction between captives and their jailers.

Azmy, who has been defending Guantánamo detainees since 2004, declared the revelation of the shooting “incredible, really amazing.”

“After 11 years of hearing about more unthinkable things — torture, beatings, indefinite detention, unexplained deaths — I think this is just the latest in a constant escalation of outrages in Guantánamo.”

The prison camps spokesman suggested that some the captives had become frustrated that world attention had moved on and were creating provocations in a bid to get sympathy and eventual release.

Among the so-called “brothers,” or detainees, Durand said, “There is a belief that public pressure, that keeping Guantánamo in the news by whatever means, will help them. The detainees’ behavior dictates the guard force response.”