For most of the last two years, Sean Larkin has worked six days a week — four days in the gang unit of the Tulsa, Okla., police department, where he is an officer, and two days in New York City to film episodes of “Live PD,” a live reality TV show about policing.

On Sundays, he traveled. For much of the fall and winter, he’d go out to Los Angeles to see a new girlfriend, the singer and songwriter Lana Del Rey. He escorted her to the Grammys. He joined her on tour. But sometimes she came to Tulsa, too.

Mr. Larkin, 46, who goes by Sticks, didn’t plan for this weird life. He likes simple things: CrossFit, mountain biking.

He grew up the son of active-duty military parents, and he attributes his interest in law enforcement to his structured home life and to life in the Bay Area during the late ’80s and early ’90s. “That’s when criminal street gangs manifested into what they turned into,” he said.