Philly Cop Watch!

The other night I was walking home in my neighborhood...(Newbold)...when I see two cop cars and two officers frisking a young African American male approximately 17-22 years old.They put him in the back of the cop car for a few minutes searching the ground with a flashlight.They defiantly noticed me standing there openly watching them .I think there is a possibility that my being there as a witness may have changed their behavior and perhaps their entire plan because they let him go....What do you think?