From 2008 to 2011, there were 1,490 complaints by detainees it oversaw, and 305 of those were fully or partially substantiated, according to Nicola Savage, a spokeswoman for G4S.
G4S had three substantiated reports of excessive force from 2007-2010, and disciplinary action was taken against the employees involved, she said.
In one of its most bizarre blunders, G4S staff attached an electronic monitoring tag to the false leg of a criminal last year. Christopher Lowcock, 29, was able to remove his leg and tag during his court-ordered curfew for driving and drug offenses. It wasn't immediately clear what Lowcock did when the tag was off.
Savage said two employees were fired in that monitoring case.
"We have 657,000 employees — some of whom are working in extremely challenging environments," she said in a statement. "While the vast majority of our employees operate to extremely high standards, on the rare instances where we find these standards to be wanting, we do take the necessary disciplinary action. The care and welfare of those in our care is our first priority."
Associated Press Writer Raphael Satter contributed to this story.
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