So in 1964 the Democratic party and the CIA had a problem. A woman who had been one of JFK's mistresses had kept a diary in which she recorded her affair with JFK, including notes about her influencing him to promote peace negotiations, and she had some very damaging inside information on the assassination.
If this had gotten out (and a few people knew the diary existed) it would have blown the Democratic party out of the water in the 1964 elections and caused media attention the CIA was determined to avoid.
So the woman, Mary Pinchot Meyer, was killed outdoors by gunshot at close range, and no attempt was made to rob anything.
Pinchot Meyer's diary was found, and handed over to the CIA-linked editor of the Washington Post. A coverup ensued . . .
Like the French say "The more things change, the more they stay the same . . . "