When you’re king of Wakanda, you get big applauses just for showing up.

“Black Panther” star Chadwick Boseman didn’t come to CinemaCon, the annual exhibition industry trade show unfolding this week in Las Vegas, to plug another “Avengers” movie. He was here to promote “21 Bridges,” a gritty action thriller that finds Boseman playing a police officer on the trail of robbers who killed eight cops in a heist gone violently wrong. But Boseman received a hero’s welcome, nonetheless, with the crowd of theater owners cheering him on as he took the stage at Caesars Palace as part of STX Films’ presentation to exhibitors.

“I’m pretty much living my best life,” Boseman said. Boseman produces the film in addition to appearing in it, and though he had many offers after dominating the box office, “21 Bridges” captured his attention with its intense look at a law enforcement officer willing to stop at nothing to get the bad guys.

“When I read the script, I could tell that it was going to be a ride,” Boseman said. “It took me back to my theater days when you have the fast-paced language like David Mamet.”

The title of the film references the lengths that Boseman goes to in order to find the killers. He shuts down all 21 bridges into Manhattan, stops trains, and cuts off the island from the rest of the world as he oversees a massive citywide manhunt. It’s personal for this particular NYPD detective, who had to deal with the trauma of having his police officer father murdered when he was a child.

In order to get into the mind of his character, Boseman went on ride-alongs, and shadowed police officers in the NYPD and the LAPD.

“At times it was a lot of fun … [but] it was horrific some of the things that you experience,” he said.

“21 Bridges” is directed by Brian Kirk (“Game of Thrones”), and produced by Joe and Anthony Russo (“Avengers: Infinity War”). Boseman was an active producer, according to STX Films chairman Adam Fogelson. He helped with casting decisions and pushed for producers to give a key role to Stephan James, one of the breakout stars of last year’s “If Beale Street Could Talk.”

“I called that one,” Boseman said.

STX Films is a relatively new player in the world of theatrical distribution. Launched in 2014, it focuses on mid-budget films such as “Bad Moms” and “The Upside” that are largely being overlooked by major studios. The studio has had successes, as well as failures such as “The Happytime Murders” and “Hardcore Henry,” but Fogelson argued that the goal has been to be “artist friendly” and to create a “collaborative, entrepreneurial work environment.”