It's good advice but unfortunately not fail-safe. Deadly force police shootings continue to occur even when a suspect complies with the rule. In these tragic deadly force police shooting cases, the cops can get off the hook by falsely claiming they only shot after allegedly seeing the victim "reach for his waistband" or engage in "waistband reaching."
In many instances it turns out the victim had no weapon whatsoever in his waistband area or anywhere else. But because the deadly force police shooting victim is already dead, unless there is video footage or independent witness testimony to speak for the victim's side of the story, the officer's version wins out.
The Ninth Circuit just addressed the troubling waistband reaching/cops-might-be-lying issue in Cruz v. City of Anaheim and concluded that just because one or more officers testify they saw the victim of a deadly force police shooting reach for his waistband or engage in waistband reaching it is for a jury to decide if the officers are telling the truth. In Cruz v. City of Anaheim, the Court reversed the lower court's summary judgment motion so now the case will go thankfully go a jury.
The Court explained that "In this case, there's circumstantial evidence that could give a reasonable jury pause. Most obvious is the fact that Cruz didn't have a gun on him, so why would he have reached for his waistband? Cruz probably saw that he was surrounded by officers with guns drawn. In that circumstance, it would have been foolish—but not wholly implausible—for him to have tried to fast-draw his weapon in an attempt to shoot his way out. But for him to make such a gesture when no gun is there makes no sense whatsoever. A jury may doubt that Cruz did this. Of course, a jury could reach the opposite conclusion. It might believe that Cruz thought he had the gun there, or maybe he had a death wish, or perhaps his pants were falling down at the worst possible moment. But the jury could also reasonably conclude that the officers lied."