Every year about 1,000 homicides are committed by people who are mentally ill and not in treatment. Many of these cases have made national headlines; in one case two years ago, a schizophrenic man killed a young woman by pushing her in front of a New York City subway. Often, the families of those with psychiatric problems must decide whether to have their children forcibly hospitalized. 48 Hours looks at this dilemma, focusing on several particularly difficult cases.