Okay. I still think it's pretty much full-on distinguished mentally-challenged to say "Oh, he got the wrong apartment building, maybe he counted the windows wrong, it's not his fault, it was an accident." When you're a cop and you're dealing with life-and-death situations, it's your fucking RESPONSIBILITY to be a little more careful and maybe double or triple-count the windows before you go in with weaponry to apprehend a suspect. A little girl is dead and most likely nothing is going to happen to the guy; that doesn't make it right, or moral.
If you're not ready to take that responsibility on, find another job or transfer to another division doing clerical work or whatever.