The tension between border town police and Navajos is real. And these people are trying to change that.

Navajo Nation Human Rights Commission says conflicts stretch back to the 1840s.

(Courtesy of Bob Fitch Photography Archive, Department of Special Collections, Stanford University Libraries) Police officers with helmets and batons on a road near the Navajo protest march in Farmington, New Mexico, 1974. Tension between police and Native people have gone on for decades.

The car chase and shootout on a desolate desert road where Colorado turns into Utah ended with Montezuma County Sgt. Edward Oxley killing Fordell Hill, a Navajo man.

It started with Oxley pulling over a car because of a broken tail light.

Oxley is now expected to go on trial in April, charged with misconduct, not for the 2018 killing, but for his actions during the pursuit.

Jennifer Nez Denetdale doesn’t see Hill’s death as an isolated incident, but rather as part of a long story about the tensions between law enforcement and Native peoples. And she believes the only surprising twist is that the officer faces charges.

She’s the chair of the Navajo Nation Human Rights Commission and has published research tracing the conflict between Navajo Nation members and border town police back to the 1840s, when white settlers began occupying areas of Navajo land with easy access to water and other resources. These outcroppings became the border towns of today.

Even border town police officials admit there are strained relations with those living in the Navajo Nation, which falls within southeast Utah, northeast Arizona, and northwest New Mexico, and borders Montezuma County in southwest Colorado. The tension appears more acute in the more populated areas within Arizona and New Mexico.

[Read more: A desert shootout spills into Utah, leaving one man dead and a sergeant facing charges]

Over time, some Navajo Nation members became reliant on these towns for basic supplies and work — especially after a U.S. government program resulted in the slaughter of over half of the livestock of different Navajo tribes from the 1920s to the 1940s.

The border towns, in turn, are reliant on the spending of Indigenous people, yet can treat them with suspicion. This suspicion leads officers to surveil these “outsiders,” Denetdale said.

“Law enforcement in border towns is all about containing and policing Indigenous people,” she said, “because we’re considered to be out of place. We’re not supposed to be in these border towns.”

In the Hill killing, the sergeant pulled over the car carrying three men for minor infractions and the sergeant had “a pretty good feeling these are bad guys” because of the way Hill held his backpack. After Oxley followed the car for a while, Hill pulled out a handgun and fired at the officer, sparking the deadly chase.

Like Denetdale, David Correia studies border town relations at the University of New Mexico. He wasn’t familiar with the Hill shooting initially. But after learning of the series of events during this dramatic chase, he also zeroed in on the initial interactions between law enforcement and Native people.

“If you’re walking down the street in a border town and you’re Native, a cop’s going to eventually roll up on you,” he said. “They’re going to demand your ID, they’re going to frisk you.”

Since the 1970s, the Navajo Nation Human Rights Commission and U.S. Commission on Civil Rights have held hearings beginning with a seminal one in Farmington, New Mexico following the murders of three Navajo men by white teenagers. Additional hearings in 2004, 2008, and 2015 included testimony describing varying degrees of police misconduct and poor relations between Navajo residents and law enforcement. Fatal police shootings of Navajo citizens in Farmington, New Mexico in 2006 and Winslow, Arizona in 2016 are cited by some as examples of how little things have changed.

Leonard Gorman, the executive director of the human rights commission, said he is focused on creating best practices for law enforcement, including cultural education about Navajo customs. The commission is advocating to diversify border town police departments and seeks improved interactions with Navajo people who don’t speak English fluently or at all.

Law enforcement officials in some areas say they have begun to address their relationship with Indigenous people. And some Navajo officials have said things have improved since the 1970s. Duane “Chili” Yazzie, a former chair of the Navajo Nation Human Rights Commission who has been an activist in the Farmington area since the 1970s, said, “The discrimination and different ways that we’ve experience racism has decreased over the years… those that wish to project those kinds of attitudes and actions against our people are more selective.” He, too, brought up the concern of police interactions with Navajo people who have a language barrier.

(Bob Fitch Photography Archive, Department of Special Collections, Stanford University Libraries) Navajo protest march with “We Are United” sign in Farmington, N. M., in 1974.

Some towns have signed agreements with the commission, though none of them are in Utah. The partnerships give Gorman some hope. Winslow — which has a history of violent interactions between police and Indigenous people — has created positions for Navajo and Hopi citizens on its Citizen Liaison Committee. Additionally, he said, Gallup, New Mexico has hired Native officers on its police force.

Steve Hebbe, the chief of the Farmington Police Department, was hired in 2014 in large part due to his experience working with Native Alaskan communities as a deputy police chief in Anchorage.

He didn’t find much outright bias within the Farmington police when he arrived, but rather a lack of familiarity with Native people.

“It’s really been an effort over seven years of sustained interaction and trying to do different things to show Farmington P.D. is a cooperative partner… in keeping everyone safe,” he said, giving as examples education and training sessions that his department has held with the Navajo Nation police, and assisting during large events in Shiprock, the closest community within Navajo Nation to Farmington.

In an attempt to reduce confrontations and potentially violent encounters, the city has started sending medics, rather than officers to respond to “man down” calls. Since the Navajo Nation bans the possession of alcohol, some tribal members purchase alcohol in border towns, many of which have large numbers of liquor stores.

Montezuma County Sheriff Steve Nowlin said he has an “open and professional, respectful relationship” with the two Indigenous nations that border or are within this Colorado county, something he attributed to a “culture change” that began when he took office. He fired Oxley after the shootout with Hill and said, “I did my job: protecting our community. Even if it has to be protecting our community from one of our own.”

“We’re here to preserve life, not take it,” he said. “We’re just asking for compliance when we enforce laws, but it’s done in a professional and respectful manner.”

However, Denetdale of the Navajo Nation Human Rights Commission said there’s been “no improvement” in relations between border town officials and Navajo citizens. “The police have immunity,” she said. “They can do anything, especially to people of color and Diné, and with very few repercussions. We know that.”

Editor’s note • This story is part of a collaboration with FRONTLINE’s Local Journalism Initiative, which is funded by the John S. and James L. Knight Foundation and the Corporation for Public Broadcasting.