Capital punishment in the United States
People who do not agree with the death penalty (death penalty opponents) say our trial system is not perfect.  Judges and juries make mistakes.  One study done by Columbia Law School found that there were serious mistakes in two-thirds of all capital trials.  In these trials, the defendants were sentenced to death anyway.  However, when their cases were appealed, over 80% of the defendants were not sentenced to death; 7% were found not guilty.