With all due respect, according to the article I'll link below, Castro was firing at police. Whether he thought he'd get away or whether it was suicide-by-cop, who knows? Allowing him to 'use up' his bullets could be deadly for the police as well as any innocent bystanders. If he made it to the car he was attempting to steal, then that vehicle becomes a weapon. Tear gas creates a fog. IMO, it's a good idea for LE to be able to see the perp. If police attempted to shoot to wound/incapacitate, there are risks there. Suppose the perp is still able to make it to the vehicle and is able to flee the scene (with LE hot on his trail) then passes out behind the wheel. That would be a huge liability to the general public.
My hubby is ex-LE and they were trained to shoot for the center of mass (chest/torso) and to assume they only had one shot to stop the perp. Aiming for an arm or leg on a target who is likely moving (and in the case of Castro, is also firing a weapon) is a nice idea in theory, but not practical in the real world. I have a lot of respect for LE and the decisions they must make in a split second.
Do I wish Castro lived long enough to tell where Pearl is? Absolutely, but as we see in the Sierra Lamar and Diana Alvarez cases, the bad guys don't always talk.
Please understand that I'm not picking on you KaaBoom. I'm just offering my perspective. All MOO.
http://m.kcra.com/news/teen-girl-reported-missing-from-vallejo/39728988