O.J. Simpson hopped behind a mic and gave a rare interview this week ... but there's one topic he won't touch after nearly 3 decades -- who killed Nicole Brown and Ron Goldman.
The 75-year-old was a surprise guest on the Nelk Boys' "Full Send" podcast ... where he talked about his 9-year stint behind bars for armed robbery, his friendship with President Donald Trump, the Kardashians and a bunch of other subjects.
But when the conversation turned to the 1994 slaying of his ex-wife and her friend, O.