An officer in McKinney, Texas, dashes down a sidewalk, losing his flashlight as he runs past a teenage videographer toward an emergency. Seconds later, the teen with the camera walks up to another officer, one who is standing with a group of kids. “I’m just saying,” the officer is saying in a calm, corrective tone that parents and school teachers everywhere will recognize. “Don’t take off running when the cops get here.”

He thanks the videographer for returning the flashlight, then listens for a few seconds as the kids around him try to explain who was and was not involved in a prior incident. “Okay, guys, I appreciate that,” the as-yet-unidentified officer says. He responds to their concerns—that the police had detained the wrong people—by saying, “Okay, that’s what I’m saying. They’re free to go.” While not casual, the officer is composed. His tone is friendly and professional as he engages with the kids.

Seconds later, another officer, Corporal Eric Casebolt, is shown interacting with some of the same kids. His angry tone and aggressive attitude stand in marked contrast to the first officer in the video. “Get on the ground,” he commands sharply while pulling on a young man’s wrist in a way that looks like he’s trying to force the man to the ground with a painful joint manipulation (technically a supinating wrist lock or, for martial arts enthusiasts, kote gaeshi).

When that proves ineffective, he grabs the back of the young man’s head and shoves him down. “I told you to stay,” he yells, pointing a large metal flashlight at someone off camera. “Get your asses down on the ground.” Like the first officer, he lectures some of the kids about running from the police, but he takes a very different approach. “Don’t make me fucking run around here with thirty pounds of god-damned gear on in the sun because you want to screw around out here.” He is anything but composed, calm or professional.

The two officers in this brief video represent two different policing styles, two different mindsets that officers use as they interact with civilians: the Guardian and the Warrior. As a former police officer and current policing scholar, I know that an officer’s mindset has tremendous impact on police/civilian encounters. I’ve described the Guardian and Warrior mindsets at some length here and here; for now, suffice to say that the right mindset can de-escalate tense situations, induce compliance, and increase community trust over the long-term. The kids interacting with the first officer were excited, but not upset; they remained cooperative. Had they gone home at that moment, they’d have a story for their friends and family, but it would be a story that happened to have the police in it rather than being a story about the police.

The wrong mindset, on the other hand, can exacerbate a tense encounter, produce resistance, and lead to entirely avoidable violence. It can, and has, caused longterm damage to police/community relations. We shouldn’t be surprised that the kids Corporal Casebolt was yelling at weren’t eager to do what he was ordering them to do—no one likes being cursed at and disrespected in front of their peers, and people of all ages, especially teenagers, resent being treated unjustly. That resentment can lead to resistance, and Police Warriors—taught to exercise unquestioned command over a scene—overcome resistance by using force.

Although the short video does not provide a complete picture of the scene, it appears likely that force in this case could have been avoided. Consider how Corporal Casebolt took issue with the way a group of girls standing on the sidewalk some distance away were “running their mouths,” so he yelled at them: “Leave!” and “Get your ass gone!” As one bikini-clad girl, 15-year-old Dajerria Becton, did exactly that, Corporal Casebolt stopped her—possibly after some verbal exchange not captured by the camera—and wrestled her to the ground. When quickly approached by two young men who appear unhappy with his treatment of Becton, he unholstered his firearm almost two seconds after those two young men began backing away from him. About ten seconds later, as Becton continued to sit on the ground where he left her, Corporal Casebolt again grabbed her and forced her down, pushing her face into the ground and planting a knee in her back as she cried. The kids now have a story about an officer, and it may well be one that sours their faith in police for years to come.

What should officers do in similar situations? For starters, they must realize that the public—even a group of non-compliant teenagers—are not an enemy to be vanquished, but civilians to be protected, to the extent possible, from indignity and harm. A Guardian mindset encourages officers to be “procedurally just,” to ensure that their encounters with civilians are empowering, fair, respectful and considerate. Research of police and military encounters strongly suggests that officers are most effective at fostering goodwill and reducing antagonism when they approach each encounter with the goal of building civilian trust.

Officers should also look out for each other, protecting their colleagues not just from harm, but also from lashing out in anger or frustration. Policing can be intensely stressful, and officers should be trained and encouraged to help their peers deal with stressful situations. When an officer is losing his cool, another officer will often be able to intervene, giving the first a chance to collect himself. That type of peer support isn’t part of modern police culture—particularly not when the officer losing his temper is a supervisor and union official like Corporal Casebolt—but it should be.

A short video of officers in McKinney, Texas, shows us the avoidable results of an unnecessarily aggressive approach to policing. But in the same video, we can see a few seconds of policing the way the way it should be done.

Seth Stoughton is a law professor at the University of South Carolina, where he is affiliated with the Rule of Law Collaborative. He served as a police officer and investigator for more than seven years. Follow him on Twitter @PoliceLawProf.