O.J. Simpson: Fear DNA Tests Will Come Up Dry

The knife buried on O.J. Simpson's former Rockingham estate may hold lots of secrets, but unlocking them may be next to impossible ... with one glimmer of hope.

We spoke with a number of forensic experts who say a knife secreted underground for 4 years is likely to become contaminated by bacteria, chemicals and various microorganisms in the dirt, making it extremely difficult to get meaningful results in DNA tests.

The experts add the natural elements pose an additional, significant obstacle to DNA tests.

Here's the glimmer of hope. We're told if the 5" buck knife was folded when it was buried, the blade might be sufficiently protected to net a DNA match.

As we reported, LAPD cops privately say they always believe O.J. used a folding buck knife to kill Ron and Nicole, even though testimony in the trial suggested a fixed blade did the job.