https://isgp-studies.com/miscellaneous/death_list/data/1977_11_Bill_Sullivan_death_FBI_hatchet_man_for_Hoover_suspected_of_JFK_RFK_MLK_assassination_involvement.pdf

That also gives a list of witnesses who died just before they were to appear before Congress re JFK death

https://isgp-studies.com/miscellaneous/death_list/data/1977_11_29_George_de_Mohrenschildt_death_CIA_friend_of_Oswald_Bush_Hunt_Sid_Richardson.pdf

https://isgp-studies.com/robert-crowley-cia-history

https://isgp-studies.com/DL_1968_04_04_MLK_death