The first assumption is that guns are five times deadlier than weapons likely to be substituted for them in assaults where guns are not available. However, many policies are aimed at handgun control, and the most logical substitute for this weapon is a rifle or shotgun rather than a knife. It is also debatable just how much of the greater deadliness of firearms used in assault is due to the weapons' technical characteristics or differences in the intention and intensity of individuals who use such weapons. Another common assumption implies that the presence of firearms encourages aggression. Findings regarding this are mixed, but several studies have suggested that guns are as likely to inhibit assaults as to incite crime. The third assumption is that the demand for guns is highly elastic, and therefore people will do without them if they are expensive and difficult to obtain. Surveys show that a large proportion of people own guns for protection or self-defense, and that laws restricting gun ownership would meet with widespread resistance and a low rate of compliance. It is among violence-prone people that demand for guns is most inelastic, and they would be most likely to violate laws or look for substitutes. Gun control advocates argue that gun ownership does not actually protect against victimization. While victims seldom have the chance to use a gun, studies have shown that burglars may be deterred by the possibility of confronting an armed victim and that assaults are less likely to be completed and result in fewer injuries when the victim used a weapon. The assumption that everyone is a potential killer because of the emotional, unpredictable nature of homicide underlies a proposed ban on all guns. Research evidence shows that the majority of homicide arrestees have prior arrest records and that felony killings account for an increasingly large portion of U.S. homicides. Therefore, legislation aimed at persons with prior felony convictions might have some potential for reducing homicides. Over 50 references are included.