Sandusky speaks out from prison; questions credibility of prosecution witness

From behind bars - Jerry Sandusky, the former Penn State assistant football coach who was convicted last June of 45 counts of child sex abuse - says he doesn't know why a key witness in the case thought something inappropriate was going on when he was showering with a boy.

Sandusky speaks from prison: Witness's 'story changed a lot'

Here's a portion of his interview with filmmaker John Ziegler, which aired on NBC:

"I don't understand how anybody would have walked into that locker room from where he was and heard sounds associated that was sex going on like he said that could've been. I mean, that would have been the last thing I would have thought about. I would have thought maybe fooling around or something like that," Sandusky said.

OutFront: Former prosecutor Wendy Murphy and criminal defense attorney Anne Bremner.