The weapon instrumentality hypothesis suggests that guns contribute to the escalation and lethality of violence. But the relationship between guns and violence might be spurious if the aggressor’s violent tendencies or the aggressor’s situation-specific intent to harm is the common cause of the presence/use of a gun and the violent outcome. To examine such rival explanations, we draw on interviews with 100 men imprisoned for an aggravated assault or homicide that stemmed from an interpersonal conflict. Each respondent described a matched pair of conflicts: the violent conflict that led to incarceration and a similar nonviolent conflict from the same time period. The matched pair design allows us to control for both potential sources of spuriousness: violent tendencies and situation-specific intent to harm. The results suggest that guns contribute to the violent escalation of conflict, but the impact of guns attenuates substantially after accounting for situation-specific intent to harm.
Source: “Have Gun Will Shoot? Weapon Instrumentality, Intent, and the Violent Escalation of Conflict” from Homicide Studies
And here‘s how to tell if someone is carrying a concealed gun.