A protester in clown make-up holds a smoke device during a May Day march that began as an anti-capitalism protest and turned into demonstrators clashing with police Wednesday, May 1, 2013, in downtown Seattle. (AP Photo/Ted S. Warren) ( CORRECTION May Day Immigration Marches Washington )
A Seattle Police Department officer pushes a demonstrator during May Day demonstrations in Seattle, Washington May 1, 2013. Protesters clashed with police in Seattle on Wednesday as a May Day rally that began peacefully turned violent after dark, with demonstrators hurling objects at officers who responded by firing flash-bang grenades and pepper spray. REUTERS/Matt Mills McKnight ( USA-MAYDAY/PROTESTS )
A lone protester taunts Seattle Police department officers during May Day demonstrations in Seattle, Washington May 1, 2013. Protesters clashed with police in Seattle on Wednesday as a May Day rally that began peacefully turned violent after dark, with demonstrators hurling objects at officers who responded by firing flash-bang grenades and pepper spray. REUTERS/Matt Mills McKnight ( USA-MAYDAY/PROTESTS )
Protesters, some with painted faces, react as a police flash-bang grenade goes off during a May Day march that began as an anti-capitalism protest and turned into demonstrators clashing with police Wednesday, May 1, 2013, in downtown Seattle. (AP Photo/Ted S. Warren) ( CORRECTION May Day Immigration Marches Washington )
A woman points out a broken window to a Seattle Police officer along the route of a May Day march that began as an anti-capitalism protest and turned into demonstrators clashing with police Wednesday, May 1, 2013, in downtown Seattle. (AP Photo/Ted S. Warren) ( CORRECTION May Day Immigration Marches Washington )
A woman gestures at Seattle Police Department officers during May Day demonstrations in Seattle, Washington May 1, 2013. Protesters clashed with police in Seattle on Wednesday as a May Day rally that began peacefully turned violent after dark, with demonstrators hurling objects at officers who responded by firing flash-bang grenades and pepper spray. REUTERS/Matt Mills McKnight ( USA-MAYDAY/PROTESTS )
Police and demonstrators clash during May Day demonstrations in Seattle, Washington May 1, 2013. Protesters clashed with police in Seattle on Wednesday as a May Day rally that began peacefully turned violent after dark, with demonstrators hurling objects at officers who responded by firing flash-bang grenades and pepper spray. REUTERS/Matt Mills McKnight ( USA-MAYDAY/PROTESTS )
A Man who was pepper sprayed is attended to during a May Day march that began as an anti-capitalism protest and turned into demonstrators clashing with police Wednesday, May 1, 2013, in downtown Seattle. (AP Photo/The Seattle Times, Ken Lambert) ( May Day Immigration Marches Washington )
Seattle Police make an arrest during a May Day march that began as an anti-capitalism protest and turned into demonstrators clashing with police Wednesday, May 1, 2013, in downtown Seattle. (AP Photo/The Seattle Times, Ken Lambert) ( May Day Immigration Marches Washington )
A protester walks away after placing a smoke device on the ground in front of police officers during a May Day march that began as an anti-capitalism protest and turned into demonstrators clashing with police lies on the ground next to police batons, Wednesday, May 1, 2013, in downtown Seattle. (AP Photo/Ted S. Warren) ( May Day Immigration Marches Washington )
Police create a barrier with their bicycles as protesters deploy smoke and march during a May Day march that began as an anti-capitalism protest and turned into demonstrators clashing with police Wednesday, May 1, 2013, in downtown Seattle. (AP Photo/The Seattle Times, Bettina Hansen) ( May Day Immigration Marches Washington )
Protesters react as a police flash-bang grenade goes off during a May Day march that began as an anti-capitalism protest and turned into demonstrators clashing with police Wednesday, May 1, 2013, in downtown Seattle. (AP Photo/Ted S. Warren) ( CORRECTION May Day Immigration Marches Washington )
Potesters react after police set up a flash-bang grenade and tear-gas bombs during a May Day march that began as an anti-capitalism protest and turned into demonstrators clashing with police lies on the ground next to police batons, Wednesday, May 1, 2013, in downtown Seattle. (AP Photo/Ted S. Warren) ( May Day Immigration Marches Washington )
A protester holds a sign that reads "this is the land of the free," while standing in a cloud of smoke and tear gas during a May Day march that began as an anti-capitalism protest and turned into demonstrators clashing with police, Wednesday, May 1, 2013, in downtown Seattle. (AP Photo/Ted S. Warren) ( May Day Immigration Marches Washington )
A Seattle Police officer is tripped up by a string held by protesters as he runs at them with his baton during a May Day march that began as an anti-capitalism protest and turned into demonstrators clashing with police, Wednesday, May 1, 2013, in downtown Seattle. (AP Photo/Ted S. Warren) ( May Day Immigration Marches Washington )
KIRO-TV reporter David Ham, left, and a news photographer at right are covered in spray string put on them by protesters as they file a report during a May Day march that began as an anti-capitalism protest and turned into demonstrators clashing with police Wednesday, May 1, 2013, in downtown Seattle. (AP Photo/Ted S. Warren) ( CORRECTION May Day Immigration Marches Washington )
Protesters react as a police flash-bang grenade goes off during a May Day march that began as an anti-capitalism protest and turned into demonstrators clashing with police Wednesday, May 1, 2013, in downtown Seattle. (AP Photo/Ted S. Warren) ( CORRECTION May Day Immigration Marches Washington )
A protester who was arrested during a May Day march that began as an anti-capitalism protest and turned into demonstrators clashing with police is carried away by police Wednesday, May 1, 2013, in downtown Seattle. (AP Photo/Ted S. Warren) ( May Day Immigration Marches Washington )
A demonstrator attempts to break a window of a pharmacy on Capitol Hill during May Day demonstrations in Seattle, Washington May 1, 2013. Protesters clashed with police in Seattle on Wednesday as a May Day rally that began peacefully turned violent after dark, with demonstrators hurling objects at officers who responded by firing flash-bang grenades and pepper spray. REUTERS/Matt Mills McKnight ( USA-MAYDAY/PROTESTS )
A Seattle Police officer runs past an overturned garbage can during a May Day march that began as an anti-capitalism protest and turned into demonstrators clashing with police Wednesday, May 1, 2013, in downtown Seattle. (AP Photo/Ted S. Warren) ( CORRECTION May Day Immigration Marches Washington )
A man is detained during May Day demonstrations in Seattle, Washington May 1, 2013. Protesters clashed with police in Seattle on Wednesday as a May Day rally that began peacefully turned violent after dark, with demonstrators hurling objects at officers who responded by firing flash-bang grenades and pepper spray. REUTERS/Matt Mills McKnight ( USA-MAYDAY/PROTESTS )
Protesters are detained by police during a May Day march that began as an anti-capitalism protest and turned into demonstrators clashing with police, Wednesday, May 1, 2013, in downtown Seattle. (AP Photo/Ted S. Warren) ( May Day Immigration Marches Washington )
Riot police prepare to confront demonstrators in Capitol Hill, during May Day demonstrations in Seattle, Washington May 1, 2013. Protesters clashed with police in Seattle on Wednesday as a May Day rally that began peacefully turned violent after dark, with demonstrators hurling objects at officers who responded by firing flash-bang grenades and pepper spray. REUTERS/Matt Mills McKnight ( USA-MAYDAY/PROTESTS )
Seattle Police officers ride on an armored vehicle as they move into position during a May Day march that began as an anti-capitalism protest and turned into demonstrators clashing with police, Wednesday, May 1, 2013, in downtown Seattle. (AP Photo/Ted S. Warren) ( May Day Immigration Marches Washington )