From what I've seen on the news, and based on what reporters present have said, the police showed extraordinary restraint. Most of the protesters conducted themselves well, but a small, very active percentage of protesters were there to instigate violence and chaos. According to many reports, the police endured viscious taunts without reacting (at one point, chanting in their faces: dead police! dead police! dead police!).
Reporters ordinarily skeptical of the police have repeatedly said that officers were put under a great deal of strain, but only responded when the protesters got physical with them. Over the entire week, there were about 100 arrests. No tear gas was deployed at any time and there are no reports of any life-threatening injuries.
This Eric Zorn commenter sums up much of what I've been hearing from others, corroborated so far by video and local media eyewitnesses:
the police acted in an appropriate and more than tolerant manner. i am a liberal and i totally respect peaceful protest and the message of the protesters. i was down at michigan and cermak at the end of the protest and let me tell you it wasn't the police who initiated the violence. there was a handful of people who seemed intent on causing a conflict and getting the press to take pictures of it. the police tolerated outright verbal abuse that was totally unnecessary and it wasn't until the protesters shoved or touched or threw something at them that the police fought back. the police showed remarkable restraint. those protesters who provoked the conflict with the police ought to be ashamed of themselves. they undermined the message of the protesters and especially of the veterans. sickening. yes the police presence was very intimidating, but they did nothing to provoke violence.
Impressively, CPD superintendent Gary McCarthy didn't sit in his war room collecting reports. He actually went down into the action to support and assist his officers, bringing them drinks (the heat was blistering), banging their helmets, telling them how proud he was of them and even jumping in to protect and assist them in some scuffles. He choked up during one interview, clearly affected by the cruelty of the taunts directed at police and the professionalism they showed in response.
If credible evidence of any police misconduct emerges in the days and weeks to come, I wouldn't hesitate to condemn it, as any regular reader knows. But I also won't hesitate to commend the police for what looks like a job very well done under extreme duress.