It’s well worth studying Seattle, since those protests were well documented and many of the police and accountability review committee records are online at the City Archives. Unfortunately many protester accounts are lost, but some are available from the University of Washington WTO History Project or from the organizers’ history project.
Some mistaken info, some slurs.
http://archives.seattle.gov/digital-collections/index.php/Detail/collections/432
https://www.seattle.gov/archive/wtocommittee/default.htm
Note that the radio recordings show that the police were firing less-lethal munitions by 8:40, while the panel 3 report puts that at about 10:00.
http://depts.washington.edu/wtohist/interview_index.htm
https://www.shutdownwto20.org/shutdownwto20
The protesters were bolder than in many other protests, but there were still negotiations for mass arrests. The police cancelled these due to staffing and budget constraints, and tried to rely on less-lethal weapons instead.
As a general impression from studying Seattle and later protests, and from local experience in DC anti-war protests, there was federal pressure to crack down and try to punish whole protest movements. Regardless of how that affects any single protest. So that led to overwhelming violence on the 2nd day in Seattle, and in Miami, and widespread infiltration and entrapment at St. Paul.