If you ask Jennifer Marshall about her day job, you’ll likely get a few different answers.

In addition to hosting The CW’s new docuseries “Mysteries Decoded,” Marshall, an LA-based private eye, is also a part-time actress with credits including roles on “Stranger Things” (as the mom of Max, played by Sadie Sink), “Hawaii Five-0” and “American Housewife.”

“I’ve never limited myself,” says Marshall. “Why not experience as much as you can? There are so many fascinating things in this world.”

On “Mysteries Decoded” (9 p.m. Tuesdays), Marshall investigates the roots of unsolved mysteries from American history, including the Lizzie Borden murder case, disappearances in the Bermuda Triangle and the Salem Witch Trials.

“This is totally different from what I do in my [daily PI] practice but it’s really been a treat,” says Marshall. “These are things that average Americans wonder about. It was such an amazing opportunity because with historical investigations, there’s usually no one to pay the bill. ‘I’m going to go down and see what’s happening in the Bermuda Triangle.’ Who’s gonna pay for that?”

“Mysteries Decoded” doesn’t shy away from the supernatural elements of each case, with Marshall consulting a wide range of experts — from the kooky (ghost hunters) to the practical (scientists and lawyers).

In between acting and hosting jobs, Marshall works at her private eye firm, Deep Source Investigations, searching for missing people, helping adopted people track down their birth parents and investigating cases of “stolen valor” — people pretending to be veterans in order to get something monetarily. It’s a personal crusade for Marshall, who spent five years in the US Navy.

“I grew up in a one-stoplight town in Colorado,” she says. “I had nine veterans in my family and I’m a fifth-generation veteran. So it was pretty much a guarantee that one of the kids was going to go into the military. My parents thought it would be one of my brothers, but it ended up being me.”

After her stint in the Navy, Marshall moved to LA to get into police work, but an injury forced her to shift gears. “I got a degree in criminal justice but I was injured in the [police] academy, and I said, ‘Let me try to go to PI school.’ That’s another way I could help people.”

Marshall says she’s been interested in acting since college and has been able to juggle her occasional acting gigs with her other work since she’s not a series regular. Acting, she says, complements her private-eye work — and vice versa.

“I’m really great at reading people. That’s a great skill for an actor to have,” she says. “People say these careers are dissimilar but I would disagree.”