A former CIA contract worker charged with beating an Afghani detainee who later died admitted he assaulted the prisoner during an interrogation, a fellow agency employee testifying in disguise said Tuesday.

David Passaro is charged with beating Abdul Wali over two days in June 2003 while questioning the man about rocket attacks on a remote base housing U.S. and Afghan troops. He is the first American civilian charged with mistreating a detainee during the wars in Iraq and Afghanistan.

"He told me that he had struck him," the other CIA contractor testified under the pseudonym Randy Wilson. "I was quite surprised about that."

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Wilson added: "He said he thought Wali was going after someone, one of the other persons present during one of the interviews."

Wilson was one of three CIA employees who testified Tuesday in disguise and under assumed names.

U.S. District Judge Terrence Boyle did not say what had been done to alter the witnesses' appearance, but all three had full hair, thick mustaches and glasses. The judge ordered a courtroom sketch artist not to draw their faces.

Passaro, 40, is charged with assault and could get up to 40 years in prison. He is not charged in Wali's death.

Defense attorneys say the former Special Forces medic never hit Wali, and gave him mouth-to-mouth resuscitation on the day he died.

The other two witnesses — a career CIA agent and another contract worker — testified that civil contractors hired to work in places like Afghanistan were not trained in interrogation techniques and were not given special rules allowing them to beat detainees.

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