http://www.tmz.com/2016/03/04/oj-simpson-knife-found-murders-nicole-brown/
Basically a construction worker found the knife and gave it to an off duty cop and the cop decided to keep it as memorabilia. He wanted to have the knife framed and put on a wall and contacted his buddy from the LAPD and that's how he got caught.
A construction worker found a knife buried on the perimeter of the former O.J. Simpson estate...
Buried knife found at OJ's estate
Basically a construction worker found the knife and gave it to an off duty cop and the cop decided to keep it as memorabilia. He wanted to have the knife framed and put on a wall and contacted his buddy from the LAPD and that's how he got caught.
A construction worker found a knife buried on the perimeter of the former O.J. Simpson estate...
Buried knife found at OJ's estate