The JFK assassination happened 51 years ago today. So this weekend in Arlington, Texas, a group of enthusiasts will gather in a Sheraton Hotel ballroom to talk about who really did it. There is an array of guest speakers lined up, including Jesse Ventura, thanks to his Conspiracy Theory with Jesse Ventura show on TruTV.

Mel Gibson was in a film called Conspiracy Theory. But if that’s what this was about, the ice would be thin, indeed. The question is, did we ever find out what Mel Gibson’s ex-wife was doing talking to JFK assassination conspiracy theorist Mark Lane?

Don’t remember that one? Let’s take a step back a moment.

Back in 2010, Mel Gibson was embroiled in a scandal of his own. His wife Oksana Grigorieva accused him of beating on her. They have since split, Mel had a lot of other issues that became very public, and he’s been hunkered down for a while.

But during all of this in 2010, Oksana Grigorieva met with Mark Lane. Now Mark Lane is considered near-royalty among JFK assassination conspiracy theory folk. He wrote a book called Rush to Judgment, which critiqued the Warren Commission report on the Kennedy killing. It was Lane’s book that popularized what has become known as the “grassy knoll theory” — the idea that Lee Harvey Oswald did not kill Kennedy, or at least did not act alone, but that someone on a nearby hill fired shots at Kennedy.

Most serious Kennedy assassination researchers now believe CIA was the primary mover in the JFK assassination. Set up Oswald in advance.

— Lisa Pease (@lisapease) November 22, 2014

Lane’s reputation is based mostly around the Kennedy work he did, as well as books that outline other conspiracy theories, including those about the Martin Luther King, Jr. assassination. But he was also present that fateful day in Jonestown when 408 people poisoned themselves with Jim Jones. He was Jim Jones lawyer.

Now that Gibson seems to be trying to repair his image and get back in the saddle as a director. He is set to direct Hacksaw Ridge, starring Andrew Garfield.