TMZ is reporting that LAPD detectives hit a dead end with the knife that was buried on O.J. Simpson‘s Rockingham estate.

Sources familiar with the situation reported the DNA testing produced no matches, as the microbes in the soil degraded any DNA to the point it was impossible to get a meaningful result. There was no hair or other sample that produced a lead.

TMZ broke the story … a construction worker found the buck knife with a 5″ blade buried on the perimeter of the property and gave it to a retired LAPD cop who was doing traffic control for a movie shoot. The cop took it home and put it in his tool box for more than a dozen years.

The LAPD have not announced the results, but TMZ is reporting the investigation is over