To acquit someone is to declare that they are not guilty.
A dream that you acquit someone can mean you think that yo may have misjudged someone, or that you are having second thoughts about a decision that you have made.
If you dream that you are acquitted in a trial, you feel that you are reaching a point in your life where others will not be able to attack you.
Watching a judge acquit someone in a dream, even though you know they are guilty, can mean that you feel that you are being blamed for something that is not your fault.