Meaning to go spread the word. To let it be known. To go tell everyone quickly.
After Antoine Dodson, a young hero from Huntsville, AL, saved his sister from an attack he left a public message for the perp letting him know that this wasn't the end of the story, and that he would be caught.
Antoine- "You don't have to come and confess. We looking for you. We gon' find you, so you can run and tell that! Homeboy!"