Prosecutors began the R. Kelly trial by telling the jury they'd see the sex tape at the center of the case "frame by disgusting frame."
Thursday they did just that, in super-slow motion. It showed just what the defense said it wouldn't: a dark spot on the man in the tape's back.
The location of the spot on the man's back appears to correspond closely with the location of a mole on Kelly's back - slightly to the left of his spine, a few inches above his waist.
Forensic video analyst Grant Fredericks, a video expert who examined the sex tape in detail, said it was "impossible" that the tape had been digitally manipulated.
Cross-examining Fredericks, defense attorney Ed Genson suggested that the spot was unclear in some of the frames, suggesting it was a digital glitch. "It comes and goes," Genson said.
But Fredericks said it could not be a glitch, adding that the spot "tracks with him and moves with (the man on the tape's) body."
Kelly's attorneys have repeatedly tried to suggest that the tape has been staged or altered with special effects, but Fredericks said it was "intact and unmodified," although he agreed that it was "likely" a fourth-generation copy.
Slowly and methodically, he also compared photos of the basement hot tub room in Kelly's home to the tape, matching dozens of knots on the wood paneling.
"It's kinda like looking at the stars - you can then map them all out," he said.
Reporters and courtroom observers had today been hoping for the explosive testimony of the Atlanta woman who says she participated in a threesome with Kelly and the alleged victim.
But Fredericks' slow, painstaking and at times dull testimony could end up being more important in deciding Kelly's fate.