How did things get out of control on University Boulevard in Tucson on the Saturday night after the University of Arizona loss to Wisconsin, when several videos showing what appeared to be police overreaction to a boisterous gathering of University of Arizona students went viral nationally?

The question is sensitive, as the Tucson Police Department reviews several of those videos, including one showing an officer who appeared to charge and violently knock down a young woman who had been merely observing the scene, as witnesses said. The Tucson Police Department has said that its officers, most of whom were wearing riot gear, arrested 15 people in and around Main Gate Square and University Boulevard on Saturday night at the conclusion of the Elite Eight game in Anaheim, Calif., where the University of Arizona lost 64-63 in overtime to the University of Wisconsin and was knocked out of N.C.A.A. March Madness. The Tucson Police Department said officers began making arrests when most of the crowd — which the police statement said numbered in the “hundreds” — did not disperse after police declared a so-called “unlawful assembly.”

In Tucson, before the game ended, 50 to 60 city police officers were lining University Boulevard in riot gear. As the crowd grew, more officers were called in, totaling 140. Some students who threw objects at officers were shot as officers fired about 200 pepper-ball rounds, as well as canisters of OC vapor aerosol (pepper spray). Police said in a statement that 15 people were arrested, aged 19 to 29, nine of whom were identified as University of Arizona students.

But at other major university campuses where students have formed equally boisterous, sometimes much larger crowds than in Tucson Saturday night, the police have taken a different approach to crowd control.

The sharpest and most timely contrast came on the very same night in Madison, Wisc., where officers estimated that there were 10,000 people gathered on State Street following Wisconsin’s victory over the University of Arizona. An estimated 50 officers were on hand from the Madison Police Department and University of Wisconsin campus force.

“The police seemed to be enjoying it with the entire community and they were there to make it safe, which I thought they did,” said Alex Haas, a senior at the University of Wisconsin. “The police were great because they allowed us to celebrate and get wild, while still being safe.”

There were no arrests – only a few citations, and no serious injuries, according to Joel DeSpain, public information officer for the Madison Police Department. Officers did not use chemical munitions or wear riot gear.

The crowd sang school songs and celebrated loudly, but around 11:30 p.m. to midnight officers let people know that it was time to head home, DeSpain said.

“Our philosophy is to have our officers out in the crowds and being mobile as they were last Saturday, and high-fiving students and having a good moment with them,” DeSpain said. “We let them know we’re also Badger fans and that we want to enjoy the moment with them, but that we want to keep everyone safe.”

As college campuses elsewhere prepared for the Elite Eight games, officers and university staff at the University of Wisconsin, University of Connecticut and Michigan State University handled planning and responses differently than in Tucson, where police prepared for weeks to handle what they described as a potential riot.

In Wisconsin, the police department held a planning committee ahead of last Saturday’s game, in collaboration with downtown business partners and university police. As Wisconsin enters the Final Four this weekend, police have already begun messaging about keeping people safe and celebrating in a peaceful way for the upcoming game.

Similarly, at Michigan State University, where the student population is nearly 50,000, there is a Celebrations Committee. Created about 12 years ago, the committee is tasked with preparing for and ensuring the smooth running of celebration events on campus. The committee includes representatives from student health services, police officers, general counsel and others.

“We want to have success in athletics and have these sort of events. We just want students to do them in a way that they don’t harm themselves and the community,” said Jason Cody, spokesperson for Michigan State and a member of the Celebrations Committee. “It only takes one incident at one celebration to give your university a bad reputation, and we obviously want to protect the reputation of M.S.U.”

The East Lansing Police Department in Michigan prepares for big events such as the N.C.A.A. tournament and Welcome Week in August by having extra officers on hand.  Police said there were no incidences related to the Sunday game, although extra officers were in town to ensure if celebrations turned criminal, they could handle those and ensure safety.

None of the officers there were in riot gear, and no large crowds had gathered, according to East Lansing Police Department Capt. Jeff Murphy.

However, local officers are no strangers to civil disturbances.

In December, thousands gathered following Michigan State’s Big Ten football championship game win, and 15 people were arrested that night, Murphy said. There were 60 fires set and property damage. In that incident, officers wore riot gear — but did not deploy chemical munitions like the aerosol canisters used in Tucson.

Murphy said that officers focus on mingling with the crowds and keeping people moving, but when a gathering  gets too big they try to maintain safety by arresting those who appear to be acting in a criminal manner. He added that if students are expecting the use of a “chemical munition,” they might wait around for it to happen.

“We would rather not use them,” Murphy said. “There’s some safety considerations about dispersing chemical munitions into a crowd and if we have another option we won’t use those.”

At the University of Connecticut, it was estimated that 1,000 students congregated in the middle of campus after the university win against Michigan State on Sunday. Students were yelling and throwing beer, bras and other underwear, and a couple were lighting newspapers on fire, according to a student report. Although there were police officers on the scene, students said the police did not use force to control the crowd.

“There were police officers, but they weren’t really getting involved with what we were doing,” said Sarah Wylie, a political science senior at the University of Connecticut. “I’m not usually overly supportive of the approach and reputation that our campus police have, but in this instance they did a good job of not being too aggressive.”

Campus police officers made one arrest and did not deploy chemical munition, Wylie said.

Although the Connecticut State Police were not on-scene for the disturbance following Sunday’s game, Paul Vance, a state police spokesman,  said his agency has supported the university police department in the past when necessary. When dispersing crowds, officers will typically just instruct students to be on their way.

There has never been an issue with students not leaving, Vance said.

“It’s very well controlled,” Vance said. “We understand the celebration students want to conduct and we don’t interfere with that as long as no one’s rights are trampled on and there’s no damage to public property.”

What about the campus police at the University of Arizona?

Brian Seastone, the chief of police at the University of Arizona Police Department , said while there is a planning process several months in advance of events like these, there is no formal committee in place for celebrations. The planning involves everyone from the Dean of Students office to the athletics department, Seastone said.

The plan for the campus is mostly developed separately from the Tucson Police Department,  although officers were involved with communications this semester. As far as involvement on Saturday, there were about 23 university police officers who helped keep streets blocked off — but campus police were not part of the Tucson city police department deployment on University Boulevard.

“There was no major damage; peace was restored very quickly,” Seastone said of Saturday’s incident. “We always look at all incidents and look what we can do better and that’s what we’re doing in this case.”

–-Forrest Gmitro, of Arizona Sonora News Service, also contributed to this report.

–Feature image by Jeffery Wick/Daily Wildcat