"The jury also heard from a psychologist who testified that Sandusky has a personality disorder that might explain the "creepy" letters he sent to one of his accusers. The defense also offered more testimony touting Jerry Sandusky's reputation as a family man and community stalwart." link
X is absolutely perfect all the time. Angelic, ideal, unreal.
If you think X has done something non-perfect you're wrong, and how dare you!
It doesn't matter if you think X has done something horrible or something trivial because this is a dichotomy (when convenient) and, as in baseball, all ties go to the runner.
If you can't prove it beyond a ridiculous doubt, it absolutely didn't happen, and, again, how dare you! Perfection sustained, move on.
If you can prove it beyond a ridiculous doubt -- dichotomy, what dichotomy? Time for hairsplitting: It's not as bad as they say. It was only this much money X stole. It was only this number of people X killed. And they weren't even real people, just semi-sub-people.
Next, of those split hairs found to be slightly ungood, they're not X's fault. Something non-X was doing that, a personality disorder, perhaps, or a bad apple or uncharacteristic mistake now removed or corrected and forever unrepeatable. Forever!
X's perfection has been established. This never happened. Delete. What never happened? As you were, X.
(This defense works better for perps like, say, a massive empire, which can make sure the prosecution's/critics' message is never properly heard and in any case has been in the jurors' homes and schools from early childhood establishing itself as an unassailable part of the jurors' own self-image. Sandusky, on the other hand, is in a bit of trouble here.)