Well how are they supposed to
Merc unarmed black people on sight? Be st them to death with nightsticks?
That's just so barbaric.
Speaking as someone with Criminal Justice education/training, "just shoot them in the X" is the wrong way if thinking. You're trained to shoot center mass (ie, the chest) since it's the biggest target. Trying to shoot tiny targets like the hands, feet or head - especially on a moving target - just leads to missing your shots
Not that the cops would've ahead of the time but the shooter was Hispanic.
Now, history has shown that knowledge probably would've made the cops get trigger happy a lot sooner, but at the time it was likely all they knew was that he was armed and actively shooting.