Teenager Pleads Guilty to Killing Her Infant Son

A teenage mother who made a tearful public plea to help catch her baby's killer pleaded guilty to murder Wednesday for killing her 15-month-old son.

An attorney for the 17-year-old girl told a Merced County juvenile judge his client suffers from bipolar disorder -- a reason county prosecutors said they did not try her as an adult.

In May, the baby's body was found in a creek. The mother, then 16, said a man had approached her in a park and run off with the child. Police arrested her seven months later.