The Department of State reports there is a prisoner transfer treaty with Peru. http://travel.state.gov/law/legal/treaty/treaty_1989.html (The United States has 12 bilateral prisoner transfer treaties in force in Bolivia, Canada, France, Hong Kong S.A.R., Marshall Islands, Mexico, Micronesia, Palau, Panama, Peru, Thailand and Turkey. In addition, the United States is a party to two multilateral prisoner transfer treaties.). Thanks to Jonathan Moore.