In response to Jackie Gaston (Your Views, Jan. 5): In 1997, Australia instituted a buy-back program for certain types of guns. Australians never had a constitutional right to own firearms. Gun ownership was restricted to members of approved sporting clubs, hunters, collectors and law enforcement. While homicides have declined a little in the past 15 years in Australia, break-ins and assaults have increased. Crime rates before and after the 1997 law show a mixed result and aren't necessarily applicable to the United States. Chicago, which has some of the most restrictive gun laws, had twice as many murders as Houston, which allows concealed carry. Guns in the hands of law-abiding citizens always deter criminals with guns.