Lindsay Clancy's Ex-Husband Patrick to Appear on '60 Minutes'

Lindsay Clancy's ex-husband testified in her defense during her murder trial, and now he's sitting down for a big TV interview with "60 Minutes."

The popular CBS program shared a teaser for the interview Wednesday afternoon ... showing members of the "60 Minutes" team micing up Patrick Clancy before he sits for the interview.

Patrick looks nervous as he sits ... before the teaser cuts to black.

The program captioned the post, "Patrick Clancy. This Sunday. Only on 60 Minutes."

As you know ... Lindsay's case has captivated the nation -- and has led to online users throwing out tons of theories that Patrick allegedly killed their three children and framed Lindsay.

Lindsay has admitted to the slayings ... and her legal team has argued she was in the middle of a psychosis-fueled blackout ... but people are still pointing fingers at Patrick -- who has since remarried and moved from Massachusetts to New York.

Patrick's attorney threatened legal action against people who spout the online theories ... while Lindsay's lawyer -- Kevin Reddington -- insists that people need to lay off Patrick.

Lindsay is still waiting to hear if prosecutors plan to bring charges against her again after the first trial ended in a mistrial. Patrick's testimony during the first trial was in Lindsay's favor ... with at least one juror saying it definitely helped her case.

It will be interesting to see what all Patrick has to say.