There is no doubt in my mind that elements within American security agencies conspired to assassinate these black leaders, directly or indirectly.

The King estate successfully brought suit against the government as per the enclosed

https://ratical.org/ratville/JFK/MLKACT/MLKACTvol14.html#VERDICT

https://www.lewrockwell.com/2014/12/no_author/the-martin-luther-king-murder-conspiracy/