There is no federal law about leaving children unattended in cars. However, eleven states have strict laws about leaving young children alone, either in cars, in public places, or at home. In those states, it is against the law to leave anyone in a car who cannot get out without help. Sometimes, when a child is sleep in the car and the parent doesn't want to wake the child up, the parent might decide to leave the child in the car and go in to the store to get something. The parent can get arrested for this. Similarly, it is against the law to leave a child alone at home or outside a public place like a restaurant. However, some states, like California,Hawaii, and Massachusetts, don't have any laws as yet about leaving children unattended in cars.