Question: Gerard already must have doubts as to Richard's guilt because Richard is investigating the one-armed man. Since there is that doubt, why would Gerard try to shoot Kimball in the chest to kill him?
Answer: Yeah, Gerard's doubts aren't enough to change the course of his expected actions as U.S. marshal when Kimble is a fugitive who was officially found guilty in the murder trial. The only thing which would grant Gerard the ability to get away with not trying to capture Kimble would be if Kimble had a whole new trial and was now found innocent, which obviously didn't happen yet. So until then, Gerard would be shirking his duties if he decided to not capture Kimble just because of doubts and there being no new innocent verdict, and that would even possibly cost him his job.
Answer: Simply having doubts does not lessen Gerard's duty to apprehend Kimble. He does not know whether or not Kimble is guilty, if he is armed, or how dangerous he is. As a U.S. Marshal, Gerard's sole duty is to capture a fugitive and return him to custody, using force as necessary.
raywest ★