[moehoward]

"Now you babble about “self defense”. Why?"

Looks like that was the justification;

"In the moments before pulling his weapon and firing, Gerlach said he saw what he thought was a gun in Kaluza-Graham’s right hand. He said he could only see silhouettes, but was afraid Kaluza-Graham was pointing a pistol at him through his back window.

“I thought, ‘This is it,’” Gerlach said."

[GJones2]

Thanks for pointing that out.