That a person is armed is usually obvious. As the article points out, “the study found police often missed “telltales” of weapon presence on the offender. Bulges, inappropriate clothing, constant touching of the gun through layered clothing, blading the body away from the officer to protect access to the gun etc.”
The cops affect not to notice. (Many cops don’t notice, believe it or not.) For a cop, stopping people because they are probably armed will get you fired as a “racist”. Besides the hoods will be back on the street before the reports are filled out.
Standard handgun training is OK but only if you know what you are doing. Probably the most important rule of self defense with a handgun that is never taught is that the gun is only drawn to shoot to kill. No hesitation, no second thoughts. Shoot. Do not threaten. Do not talk.
Obviously if possible one takes as strong a defensive position as time allows. A defensive position ideally will provide cover from fire, concealment from the enemy, and opportunities for maneuver (read: “running away”).
It’s probably not taught because, among other things, in a lot of places it will get you put in prison even if you were the otherwise innocent unoffending participant in the fatal event.
In a lot of places it is or has been the “law” that when you draw and shoot in self defense you should be shooting to stop the offender from committing whatever offense was or was about to be committed. The object is to stop the offense and you can shoot till it is stopped. Killing of the offender can be a side-effect but it is not supposed to be the goal of the shooting. If you say you intended to kill, you may be prosecuted.
Of course, maybe it’s different in Wisconsin.