Early in the show there was discussion relating to placing DNA within the context of other evidence in any given investigation, DNA is only one piece of a puzzle.
All that was said with respect to DNA as it relates to the JonBenet case, specifically, is the following:
The main DNA in this case, (from the crotch of the underpants of JonBenet) produced a PARTIAL MIXED profile with an unknown male source, (a minor contributor,) which was placed in the FBI database, CODIS.
That DNA, which is unquestionably the STRONGEST profile of all, (excluding JonBenet,) would be INADMISSIBLE in court according to Dr Krane.
The reason is that the DNA without a statistical weight is meaningless and, at least for the present, there is no reliable method available to give statistical weight to a mixed sample with dropout. The dropout refers to the fact that 3 out of 13 areas revealed no genetic information.
The statistical weight refers to the often insanely high numbers you hear at a trial.
For example, you may have heard something along these lines:
Ladies and gentleman of the jury, the DNA shows that the chance that "the probability of a randomly selected, unrelated individual having contributed DNA to this sample is approximately 101.5 quadrillion to one."
That number, 101.5 quadrillion to one, is a calculated statistical weight.
What Dr Krane is saying is that with the DNA in the JonBenet case, you cannot attach a statistical weight because the test results are inconclusive.
If you can't attach a statstical weight, you can't show up in court with it.
The other main point is that Dr Krane said that if Mary Lacy based the exoneration of the Ramseys exclusively on the DNA evidence in this case, then that was an overreach, and THAT THAT CONVEYS A LACK OF UNDERSTANDING OF DNA.