It's going to turn out to be a fraud that the ex-officer had framed in his house. My first choice based on the timing coinciding with the documentary is that the whole thing was made up to make money selling the knife. Here's the story: Supposedly a construction worker found the knife when they were tearing down the Simpson mansion to build a new one. He then handed it over to an off-duty cop in an on-duty uniform (which they are allowed to wear) working across the street as a private rent-a-cop for a movie being made. The off-duty now retired cop, instead of turning the knife in, had it farmed and hung in his house as the OJ murder knife (because people are that weird). It supposedly hung there for years until it came to the attention of the LAPD who took it into custody a month ago and are having it tested for DNA. The cop supposedly thought the case was closed. It wasn't and never will be because Simpson cannot be tried twice even if this turns out to be the murder weapon. No one in the LAPD doubts OJ was the murderer. But the case remains open until there is a conviction. The fact the retired cop didn't admit his framed knife was a fraud meaning he might be guilty of not turning over evidence suggests the story about a construction worker finding the knife could be true. But his belief the case was closed is also plausible and he may not be worried about his actions. I say the most likely explanation is he tried to sell the knife (after all there is that OJ documentary airing right now and maybe he got tired of the morbid thing on the wall), or less likely but still plausible, someone who saw it said something to the LAPD and they acted. I think he made the construction story up. He may have put the knife up as a conversation piece, a fake memento for whatever morbid reason people collect murder memorabilia. Who thinks it was really found at OJ's mansion and might really be the murder weapon? I should add for those that don't know the case, OJ was seen throwing something away in an airport trash can and it's thought that could have been the murder weapon that was never found.