In more than half of American homes where there are both children and firearms, according to a 2000 study, the weapons are in an unlocked place, and in more than 40 percent of homes, guns without a trigger lock are in an unlocked place. Almost three-quarters of children under the age of ten who live in homes with guns say they know where the guns are. A 2005 study showed that more than 1.69 million children and youth under eighteen live in homes with weapons that are loaded and unlocked. According to a Department of Education study, 65% of school shootings between 1974 and 2000 were carried out with a gun from the attacker's home or the home of a relative. And the laws, it seems, are effective. One study indicated that in the twelve states where child-access prevention laws were on the books for at least one year, unintentional gun deaths fell by 23 percent.