I had so much research on this that I didn't save :(

From what I can remember, Matt Couch was part of America First Media that was investigating the murder of Seth Rich. There was another group that was ran by Jack Burkman, who the FBI tried to kill https://www.washingtonpost.com/local/public-safety/conservative-lobbyist-was-attacked-outside-his-arlington-home-tuesday-evening-police-say/2018/01/17/9e9340d6-fba4-11e7-a46b-a3614530bd87_story.html

Basically they had different narratives about what happened to Seth Rich. Matt Couch had all of the info that surrounded Seth Rich's murder. He was able to find out that it was MS-13 gang members working for the FBI, but never got further than that.

Frank Whalen, who worked for America First Media, originally sent the Ryan D. White whistle blower letter to Judicial Watch and Congress (intelligence committee?) I suspect that Matt Couch had the whistleblower information for a long time but never released, instead throwing out bits and pieces of it. He eluded to not being able to release info because he could be sued. I think Whalen got tired of it, left the group, and tried to get the whistleblower in contact with anyone that could do something about it. Lin Wood eventually got the letter, probably from a staffer in Congress that found it or a staffer from Judicial Watch. Finally, Lin Wood interviewed "Ryan D. White" and got all of the information to us.

It seems like alot of people involved in the private investigations into Seth Rich's murder didn't really want to solve the murder. They just wanted to profit from it by turning into this unsolved cold case.