Depends on how many results it brings you -- if it declares 10 candidate matches, and 1 is correct, then its still 90% wrong -- but still very useful.
When you give them less lethal weapons what happens is that they just use them in every possible situation and often they increase lethality by aiming at vulnerable body parts or shoot them from a very short distance. What they really should do is show some restraint and not let themselves get provoked easily.
Facial recognition is basically ending in the same situation. 96% failure rate means you have a lead but not evidence and only get to interview people for more clues. Instead they just arrest the leads because the wanted criminal could attack during the interview or flee afterwards.