He was trying to "get justice" for them two years before they were killed?
There was a MA pol, Dianne Wilkerson (D, female of color) that put forward the excuse that she didn't pay her Federal taxes because she needed the money to put in an alarm system after she got death threats. The failure to pay was a year before the threats.
She was convicted and had to do the ankle bracelet thing. MLK's widow, Coretta Scott King came to Boston, and as much as the tax cheat tried, King's handlers kept them far enough apart to avoid any photo op "chumminess" for the next election.
About a decade later, in a bribery investigation, she got caught stuffing benjamins in her bra, on camera, by the FBI.
Probably a candidate for a Obola pardon...