Try and account for that period of time on your resume.
Q: Mr. Ramirez, I noticed a gap on your resume. Could you explain this?
A: Yes, Sir. I was falsely accused of raping a sixteen year old girl after kidnapping her at gunpoint. During the time in question, I was an involuntary guest at the state correctional facility.
He can also use the guys on his old cell block as references.
I can tell you how one guy accounted for it. We had an employee who described killing his wife to another employee. I had to check that out. Seems that he found his wife in bed with another man and shot her ("Right between the eyes, just a lucky shot"). He didn't really cover it up but the employment agency did. They listed his employment with them for the ten years he was in prison. We got rid of him and the agency.