** I am not a lawyer or have any legal training, but this is how I personally view the sign. Also, the example I give may be flawed, but I think it demonstrates the point well and can be applied to more accurate circumstances. **

Another example is that you committed a crime, but not the crime they are trying to charge you with.

For example,

You and a friend rob a store. You didn’t know it going into it but your friend brought a gun.

You get arrested and you both get charged with armed robbery.

You are not guilty of armed robbery since only your friend had a gun. They would have to charge you with a crime that was accurate.