https://www.biography.com/actors/a43658702/matthew-mcconaughey-and-woody-harrelson-related

Recently coming out that these two are half brothers.

They also look so similar. H-wood is likely a lot more related due to hidden fathers and couple swapping then people realize.

They were discussing how close they and their respective families are when Kay said she “knew” Harrelson’s father, Charles.

Charles Harrison was a notorious hitman convicted of two separate murders that occurred in 1968 and 1979, respectively. He died in 2007 at Colorado’s Supermax prison where he was serving two life sentences.

“Everyone was aware of the ellipses that my mom left after ‘knew,’” McConaughey said during the podcast. “It was a loaded K-N-E-W.”

McConaughey said he figured out Key was in the middle of her second divorce with his believed-to-be father James Donald McConaughey, who died in 1992, when Harrelson’s father was on furlough. There is possible evidence indicating she and Harrelson might have had a meeting, or a “knew moment” as The Dallas Buyers Club actor put it.

Charles Harrison was also believed to have been involved in JFK's assassination.

https://en.wikipedia.org/wiki/Charles_Harrelson

Charles Voyde Harrelson (July 23, 1938 – March 15, 2007)[1] was an American hitman and organized crime figure who was convicted of assassinating federal judge John H. Wood Jr., the first federal judge to be assassinated in the 20th century. Charles Harrelson was the father of actors Brett and Woody Harrelson

On March 15, 2007, Harrelson was found dead in his cell, having died at the age of 68 from a heart attack

Sounds like they "retired" him.