“For me, it all came out of that [role], of seeing people have a real interest in learning about forensics and everything that goes into an investigation,” Harper, 54, says of “How It Really Happened with Hill Harper,” now in its fifth season as HLN’s longest-running, most-watched original series.

“In a way, it’s a combination of those things and the fact that technology is continuously evolving — and, as cases are examined, there’s always something new.”

“How It Really Happened,” which premiered in 2016, blends archival footage, interviews and expert analysis with Hill (who’s also a producer on the series) providing wraparound narration. This season’s topics include the 1999 murders of three women in Yosemite National Park (airing Sunday at 9 p.m.); the death of Tom Petty; Siegfried & Roy; the murder of Michael Jordan’s father, James Jordan; and the 2013 Boston Marathon bombing.

“Some of the cases we do about celebrities are more about telling their stories. They’re homages,” he says, alluding to a “How It Really Happened” episode devoted to Prince. “Prince was actually a friend of mine and that episode was something very personal to me. It’s the same with Tom Petty — I didn’t know him personally, but we’re telling stories of who these people were and what they did … in a really respectful, supportive, positive way.

‘As cases are examined, there’s always something new.’

“We have to pick and choose,” he says of the subjects covered each season, into which he also has input. “We’re telling some of these stories because they’re happening right now. It doesn’t take a brain surgeon to tell you that Siegfried & Roy were the original ‘Tiger Kings,’ ” he says, alluding the headline-grabbing Netflix documentary. “And while [the ESPN documentary] ‘The Last Dance’ touched upon the death of Michael Jordan’s father, it didn’t go into it deeply in any kind of way.

“There are some cases I would like to see in which we take the title of the show and extend it to issues,” he says. “For instance, and I haven’t been able to sell this yet, something like a ‘How It Really Happened’ about the murder of 2,000 young men of color in Chicago. I would like to tell the story around Dylann Roof and about that horrible tragedy in the church in South Carolina … letting people see the true problems with racism and violence.”

Hill, who co-stars as Dr. Marcus Andrews opposite Freddie Highmore on ABC’s “The Good Doctor,” says the medical drama will tackle the pandemic in its first two episodes of the upcoming season — slated to begin shooting in Vancouver with strict protocols in place.

“It would be tough to tell a story within a hospital and not deal with that,” he says. “I was in Detroit for most of the shutdown and every other day there was a funeral procession going past my place. To be able to tell stories and honor the frontline workers … is a real honor for me.”