- Brenda Spencer, 17 years old, opened fire on a crowded elementary schoolyard with a semi-automatic rifle because "Mondays always get me down." - Timothy Dwaine Brown, 16 years old, beat his brother to death before killing his grandparents in cold blood. - Molested repeatedly by her father, 16-year-old Cheryl Pierson hired a classmate to execute him. - Two Missouri brothers, ages four and six, attacked and brutally murdered a baby girl because "she was ugly." There is a new breed of killers loose in America today -- and its numbers are growing at an astounding rate. They are responsible for over ten percent of the nation's homicides. They are often victims themselves of neglect, violence and sexual abuse, of drugs and poverty. They murder alone or in groups -- in anger and frustration, for attention . . . or for thrills. And they have one thing in common: they are all children.