In today’s world police are an endangered species and are often deliberately targeted by folks with a definite attitude problem.  Similarly armed miscreants whether burglars, car thieves, drug dealers or folks with domestic partner issues carry guns for a reason.  Shooting an officer of the law is their first line of defense against being detained or deterred from their nefarious missions.  It is not unreasonable to expect armed officers to shoot first and ask questions later when coming upon a gun wielding individual innocent or not in an investigation situation.  It is simple precaution in a dangerous environment to avoid being another innocent officer of the law gunned down.  Unarmed police would not be reassuring either to folks calling 911 needing help from someone with a gun.

The other option is to take more guns out of the hands of civilians.

Complete story at this link: https://www.cnn.com/2018/08/03/us/man-mistaken-for-intruder-and-shot-by-police-trnd/index.html