During nearly 40 years of investigative journalism, "Frontline" has crisscrossed the world, reporting on everything from the rise of Vladimir Putin in Russia to the fall of apartheid in South Africa.

This time, the focus is on us.

"Police on Trial," debuting at 9 p.m. Tuesday on TPT, Ch. 2, examines Minneapolis law enforcement in the wake of George Floyd's murder, how much has changed — and how much hasn't. To pull it off, a crew for the award-winning PBS series partnered with the Star Tribune, tagging along with several of the paper's journalists over a two-year period.

Crime reporter Libor Jany, a key player in the Star Tribune's Pulitzer Prize-winning coverage for breaking news, serves as the narrator.

"I was entirely opposed to it. Being on camera isn't my cup of tea," said Jany, who now works at the Los Angeles Times. It took several meetings over coffee with director Mike Shum to persuade Jany to take the starring role. "The more I thought about it, the more I realized that my preference to stay behind the scenes was less important than being part of a very serious journalism endeavor."

Executive Editor Suki Dardarian didn't have as many reservations.

"I was really intrigued," said Dardarian, who was managing editor when producers approached the paper. "While we have great videographers, we've never been part of putting together a documentary like this. I felt that if the story of what the Twin Cities experienced was going to be told to a national audience, this was a good way to do it."

"Frontline" is no stranger to Minnesota. Excerpts from a 1986 episode about a halfway home for the mentally ill in St. Paul were featured in a Pearl Jam video. But this was the first time producers have worked so intimately with the local media.

The series has stepped up its collaborations with other media companies, including the Tampa Bay Times, which won a Pulitzer Prize this year for a joint project that looked at hazardous conditions at a Florida lead smelting plant. The uptick in partnerships is due to the Local Journalism Initiative, a grant consisting of $3 million from the Knight Foundation and $1 million from the Corporation for Public Broadcasting.

"We really see our role as supporting investigative journalism at a local level," said "Frontline" Executive Producer Raney Aronson-Rath, who oversees the Initiative, now in the third year of its four-year mission. "People trust their local papers more than the national press."

Aronson-Rath and her team tapped Shum to direct, in large part because the filmmaker lives in St Paul. But Shum had only moved to the area less than eight months before Floyd's death. The best way to tell the story, the Denver native decided, was through the eyes of veteran reporters with deep knowledge of the area and the Minneapolis Police Department.

Some of the 90-minute film captures rather routine practices: Zoom meetings between editors, reporters knocking on doors for comments, writers huddled over their laptops in the middle of the night.

But there also are moments of high drama, like when reporter Liz Sawyer hurries to slip on a gas mask when police try to break up a protest with tear gas. On the eve of covering the Derek Chauvin trial, reporter Chao Xiong opens up to his colleagues.

"I don't know how we're going to get through the next few months," he tells them. "I don't think I'm ready for it."

In the following scene, we see him driving to the courthouse, confessing that he got only three hours of sleep.

"We love journalists and we love to see them doing their job," Aronson-Rath said in a phone interview last week. "Reporters have a nuanced, sophisticated way of speaking about their own community that makes for great storytelling."

Xiong, now managing editor of the Minneapolis-based Sahan Journal, said it was initially "nerve-racking" to have cameras accompany him on assignments and to sit for interviews.

"You're surrendering your story to someone else, the same way our sources usually have to do with us. We're not used to it," Xiong said just before Shum filmed him sharing some final comments in a Star Tribune studio. "But in the end, it was pretty natural. You're so busy and caught up in the moment, you don't think about the crew following you around."

Xiong and his former Star Tribune colleagues are quick to point out that the final film doesn't rely on their work alone.

"Frontline" producer Marcia Robiou also played a key role, convincing former Minneapolis police officers to share how they tried to improve the department from within. Some of those interviews took more than eight months to secure.

"It was really difficult to get them to speak on camera," Robiou said from her home in Walla Walla, Wash. "They knew this was a divisive issue and wanted to make sure they could trust me to tell their stories in an accurate way. But I think ultimately, they realized this was a national audience that they could reach and show them that there are police officers trying to do the right thing."

The reporters from the TV and print worlds consider the final product a true collaboration.

"I feel like I'm part of the Star Tribune family," Robiou said.