If you go to a prison and ask people whether they’re innocent, many will tell you that they are. While a cynical person may roll their eyes and assume that everyone is lying, you may ask yourself a deeper and more meaningful question: How many of those people are telling the truth?

It’s hard to know for sure, but some studies point to about 1% of all people who are behind bars actually being innocent. They have even called this a conservative estimate. It’s clear that some people slip through the system and get convicted when they really did nothing wrong.

Now, 1% may sound like a tiny number, but you have to think about the massive size of the prison system in the United States. Say that 1% is accurate. That means there could be around 20,000 people in jail for no reason whatsoever. Many of them are the same people telling you they’re innocent, people that your cynical counterpart in this hypothetical situation wouldn’t believe. But they’re being honest and they are innocent.

Why does this happen? There are many reasons. Eyewitnesses make mistakes. Juries make mistakes. Judges have inherent biases. Some people even plead guilty when they are not, for a variety of reasons — such as intimidation by the authorities.

If you are facing legal charges, it’s important to know that the system is not perfect. The courts do get it wrong, as they have for tens of thousands of people already. That’s why it’s so crucial to have a great criminal defense team on your side.