It was revealed on December 13, 2007 in the report by Senator George J. Mitchell that Vaughn had purchased steroids or other performance-enhancing drugs from Kirk Radomski , who said he delivered the drugs to him personally. Radomski produced three checks, one for $2,200 and two more for $3,200, from Vaughn, one of the latter dated June 1, 2001, and another dated June 19, 2001. Radomski said that the higher checks were for two kits of HGH , while the lower one was for one and a half kits. Vaughn's name, address and telephone number were listed in an address book seized from Radomski's house by federal agents. Vaughn's trainer instructed him to take HGH in attempt to recover from injury.