A little research shows that my hesitation to buy into your assumptions was warranted:

Friday evening in downtown Kent began peacefully with the usual socializing in the bars, but events quickly escalated into a violent confrontation between protestors and local police. The exact causes of the disturbance are still the subject of debate, but bonfires were built in the streets of downtown Kent, cars were stopped, police cars were hit with bottles, and some store windows were broken. The entire Kent police force was called to duty as well as officers from the county and surrounding communities. Kent Mayor Leroy Satrom declared a state of emergency, called Governor James Rhodes' office to seek assistance, and ordered all of the bars closed. The decision to close the bars early increased the size of the angry crowd. Police eventually succeeded in using tear gas to disperse the crowd from downtown, forcing them to move several blocks back to the campus.

The next day, Saturday, May 2, Mayor Satrom met with other city officials and a representative of the Ohio National Guard who had been dispatched to Kent. Mayor Satrom then made the decision to ask Governor Rhodes to send the Ohio National Guard to Kent. The mayor feared further disturbances in Kent based upon the events of the previous evening, but more disturbing to the mayor were threats that had been made to downtown businesses and city officials as well as rumors that radical revolutionaries were in Kent to destroy the city and the university. Satrom was fearful that local forces would be inadequate to meet the potential disturbances, and thus about 5 p.m. he called the Governor's office to make an official request for assistance from the Ohio National Guard.
Members of the Ohio National Guard were already on duty in Northeast Ohio, and thus they were able to be mobilized quickly to move to Kent. As the Guard arrived in Kent at about 10 p.m., they encountered a tumultuous scene. The wooden ROTC building adjacent to the Commons was ablaze and would eventually burn to the ground that evening, with well over 1000 demonstrators surrounding the building. Controversy continues to exist regarding who was responsible for setting fire to the ROTC building, but radical protestors were assumed to be responsible because of their actions in interfering with the efforts of firemen to extinguish the fire as well as cheering the burning of the building. Confrontations between Guardsmen and demonstrators continued into the night, with tear gas filling the campus and numerous arrests being made.
Shortly before noon, General Canterbury made the decision to order the demonstrators to disperse. A Kent State police officer standing by the Guard made an announcement using a bullhorn. When this had no effect, the officer was placed in a jeep along with several Guardsmen and driven across the Commons to tell the protestors that the rally was banned and that they must disperse. This was met with angry shouting and rocks, and the jeep retreated. Canterbury then ordered his men to load and lock their weapons, tear gas canisters were fired into the crowd around the Victory Bell, and the Guard began to march across the Commons to disperse the rally. The protestors moved up a steep hill, known as Blanket Hill, and then down the other side of the hill onto the Prentice Hall parking lot as well as an adjoining practice football field. Most of the Guardsmen followed the students directly and soon found themselves somewhat trapped on the practice football field because it was surrounded by a fence. Yelling and rock throwing reached a peak as the Guard remained on the field for about ten minutes. Several Guardsmen could be seen huddling together, and some Guardsmen knelt and pointed their guns, but no weapons were shot at this time. The Guard then began retracing their steps from the practice football field back up Blanket Hill. As they arrived at the top of the hill, twenty-eight of the more than seventy Guardsmen turned suddenly and fired their rifles and pistols. Many guardsmen fired into the air or the ground. However, a small portion fired directly into the crowd. Altogether between 61 and 67 shots were fired in a 13 second period.
http://dept.kent.edu/sociology/lewis/lewihen.htm