what cappy said. a shoulder shot seems to be cutting it close though; can be deadly if it hits the wrong shoulder. but a leg shot is too hard to pull off reliably, so its hard to say for sure
You should generally aim for the lower midsection which is the least lethal place you can shoot fairly accurately. (shoot to wound) Stomach shots are the most painful but aren't lethal unless left untreated. Shooting an armed suspect in the upper chest is too dangerous and may leave the suspect dead (shoot to kill)
It resembles a game of chicken when you think about it

Swerve can mean "gives up" for suspect, and "doesn't shoot" for cop. Continue can mean "shoots" for both parties. The worst case scenario is if both the suspect and more than one cop ends up dead (dallas sniper attack). The unfavorable but not worst scenarios are if the suspect shoots the cop or the cop shoots the suspect. The best outcome is if the cop doesn't shoot lethally/disarms the suspect and the suspect either gives up or is disarmed.
Aiming for the best outcome is what all cops should try to do. However, it can be understood that it's not always possible.