The two whose stories we know were mentally ill.
Blacks have long prided themselves on not being mass murderers the way white men are. Add in the DC snipers and the guy at the Navy yard, however, and we’ve got full racial representation in that bunch.
The common denominator FWIW is mentally ill men. The dental hygienist seems to have broken the glass ceiling on suicide by cop, however—if that was her intention.
That went out the window in 1981/82 with Wayne Williams killing twenty-some children in Atlanta.