A new study just released by the Proceedings of the National Academy of Sciences determined that 1 in every 25, or 4.1 percent, of people on death row, are innocent. But the innocence rate is more than twice the rate of exoneration. That means an unknown number of innocent people have been put to death. „Every time we have an execution, there is a risk of executing an innocent. The risk may be small, but it‘s unacceptable,“ said Richard Dieter, executive director of the Death Penalty Information Center.