Chicago police scuffle with demonstrators during a protest march and rally at this weekend's NATO summit in Chicago Sunday, May 20, 2012 in Chicago. (AP Photo/Paul Beaty)
May 22, 2012 7:32:11 AM PDT
SOPHIA TAREEN Associated Press
CHICAGO - May 21, 2012 --
The sight of Chicago police raising billy clubs against demonstrators Sunday was the kind of image that has dogged the city's police force longer than most of those who clashed with protesters have been alive.