I looked into the actual House Assassinations Committee evidences at the National Archives. I looked at the wiretaps. The evidence isn't there.

As for Hoover, you're wrong on both points. The FBI under Hoover did an investigation in the 1940s called "Re-Investigation of the Capone Gang" until it was shut down by the attorney general. There was limited investigation until Apalachin in December 1957, then he believed that the Mafia was a national problem and authorized all those bugs. Who do you think handled Joe Valachi and Greg Scarpa? The FBI. The FBI under Hoover also investigated the Mississippi Burning case (the one where they used Scarpa to put the fear of God into a Klansman).