Turns out a Chicago jury doesn't think R. Kelly's a pedophile ... Six years after the R&B singer was busted for a sex tape allegedly featuring him with an under-age girl, the Grammy winner got off (pun intended) and got out of the 15 years in prison he faced if found guilty.

The jury says IT WASN'T KELLY! And how do they know? The guy in the sex tape didn't have a big mole on his back like R. does.

Kelly's lawyer, Sam Adam, Jr., told jurors while looking at a freeze-frame from the video where it could be seen clearly that there was no mole on the man's back, "It ain't him. And if it ain't him, you can't convict."

Not as poetic as "If the glove doesn't fit, you must acquit!"