But this wasn’t a doppelganger situation; both Marvin and Mateo were potrayed by actor Julian Works.
He was in9-1-1,'“Lone Starco-creator and showrunner Tim Mineartells EW.
And I couldn’t disagree with that.

Julian Works as Mateo (left) and Marvin on ‘9-1-1: Lone Star’.Kevin Estrada/FOX; Fox
And I said, ‘You know what?
We can just later say that Mateo and Marvin are cousins.'”
“But that became cannon at that point.”
“Mateo gets a phone call from his cousin who’s in trouble.
“It’s a gimmick in the sense that it’s a highly stylized choice,” he explains.
Or ‘How’s that going to work?’
So this episode is a good treat for the fans.
It was definitely fun to play, and I was so excited.
I couldn’t wait to step on set and do my thing.”