JW Cortes may be known best as Detective Alvarez on the TV show 'Gotham,' but today he was invited to be the principal at M.S. 136 in Sunset Park.

Cortes stepped in for principal Eric Sackler, with hopes to inspire.

"He's someone who came from the neighborhood, lived right where they lived and now he's really succeeded," says Sackler.

Coretes says he always loved the arts, but things didn't come easy to him. When he was a child, Cortes says he grew up on a block notoriously nicknamed by the NYPD as "Little Vietnam." After graduating high school, Cortes joined the military and served one tour in Iraq. He says it was there he realized something was missing.

"I decided, 'Wow life is short, if you have dreams the best time to pursue them is now,'" he says. 

In addition to his acting role, Cortes is an MTA police officer. 

Cortes says he will be back at the school throughout the year, and when the class graduates. He will be delivering the speech as the keynote speaker to make sure every kid walks across the stage and gets their diploma.