Why did he have to use deadly force?
He could have done many different things to resolve the situation better.
He could have talked to the spider in a gentle manner so he won't hurt the spider's self esteem and persuade the spider to squat elsewhere and maybe get some education and a job and buy its own car.
He could have just taken the spider in his cruiser and dropped it off in another jurisdiction.
He could have helped the spider through a tough time because we all know the spider was just turning its life around and trying to connect with its 1,568 hatchling spider babies that never got to know its spider dad before spider dad went to spider jail because the spider man kept him down with racist laws which gave him no chance in life other than to commit spider crimes.
Or... he could have just shot the spider out of the woman's car... but that requires more training on the department's end.
Cool story, bro... when do you get to the part where you shut up and walk away from me?