Look, Babb was brandishing a rifle with a scope at police. In his condition--- he had fired a 9mm handgun in his home--- he could have shot a person blocks away. This wasn't the unwarranted killing of an unarmed fellow going about his regular day. You do make one point: Babb was white. Babb was a former officer in the Army. What happened was terrible, a horrible PTSD episode and tragic--- but one simply cannot fault the police. When Babb picked up his rifle and pointed it, he sealed his fate. 
If Babb had been black, do you think the reaction would in any way have been similar?