I also don’t have first hand knowledge, either, but my understanding is that officers are not trained/taught to “shoot to wound” because it is much more difficult than shooting at the body (and so the officer is much more likely to miss his/her shot), and also because wounding a person may not neutralize their ability to strike back.
Some additional info:
Here's why police don't shoot to wound in the case of deadly force
www.ajc.com
Maybe these practices should be changed, but I can certainly understand the arguments against “shooting to wound.”