One of the photographs submitted by Brian McNamee, former personal trainer for pitcher Roger Clemens, showing evidence of alleged use of steroids by Clemens. (AP Photo/Emery Celli Brinckerhoff & Abady, Senna Riahi)
DNA on medical waste matched Clemens'
A forensic scientist testified Friday that two cotton balls and a syringe needle allegedly saved after a steroids injection tested positive for Roger Clemens' DNA.
Trainer testifies in Clemens trial
McNamee: 'Misspoke' about evidence
McNamee admits lying about steroids
