The illustration above, created by Megan Jaegerman in 1992 and revised for Edward Tufte’s Beautiful Evidence, shows how to tell whether a person is carrying a weapon. The person’s movements will be awkward because of the weight of the gun, and he or she will take steps to conceal it from observers.
It is very important that police make this determination correctly. National data on victims of police shootings are not available, but an investigation by the Las Vegas Review-Journal a few years ago found that about one in ten people shot at by police there were unarmed. Of that group, a disproportionate number — about half — were black. The newspaper also found that Las Vegas police used their weapons more frequently than police in other major metropolitan areas. Click below for the report.