Another example of letting the human mind make inferences /assumptions by not supplying all the info. "Imagined Testimony":
SO, MR. _____ expert, HOW LONG does it take to degrade.?
Well, it would take longer than the time between Danielle's disappearance and the time we found this stain and tested it.
SO why didn't you test another cell?
"Well, they were all the same, it wasn't possible to prove it was DANIELLE's only, it could be Brenda's, but that would ruin our case, and I wouldn't get paid!"