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Wrongful convictions are as old as justice itself, and any system of criminal justice is a human endeavor, which will inevitably make mistakes. However, it wasn't until the advent of DNA testing that these mistakes were exposed beyond a shadow of a doubt. DNA has changed the criminal justice system forever: thousands of people have been convicted based on DNA evidence, and more than 220 have been exonerated. Other forms of evidence have also overturned thousands of convictions, but the standard is proof in non-DNA cases is much, much higher.
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