NEW YORK – In torn jeans and saddled with a black backpack, Andrew Witten glances up and down the street for police. The 51-year-old then whips out a black marker scribbles “Zephyr” on a wall covered with movie posters.

He admires his work for a few seconds before his tattooed arms reach for his daughter, holding her hand as he briskly walks away.

Witten and a generation of urban latchkey kids who spray-painted their initials all over Manhattan in the 1970s and ’80s and landed in the city’s street art scene are coming of age – middle age, that is.

And like Witten, a 51-year-old single father, some street artists considered now to be graffiti elders are having trouble putting away their spray paint cans. As Witten says, “I’m ready. I could go tonight.”

“I’m chronologically old to be out there doing it,” Witten admits with a playful smile. “I’m sure I can’t run quite as fast.”

Witten built a reputation as a master at spray-painting extravagant graffiti pieces on freight and subway trains, called train-bombing, in the neighborhoods where he now teaches his 6-year-old daughter, Lulu, to skateboard. For him, spray-painting other people’s property with his nickname, or tag, is almost an addiction, and danger is part of the drug. Crawling under barbed wire, ducking from police officers, even being shot at is all part of the experience.

Witten describes painting graffiti in more poetic terms. He calls it a freeing experience, in which the silence of night gives way to the hiss and mist of the spray rising into the moonlight.

Angel Ortiz recently served 41 days of a 50-day sentence in the Rikers Island jail system after being busted for spraying his tag, LA Roc, on a billboard in March of last year. For decades, Ortiz, 45, has been known on Manhattan’s Lower East Side as LA II. A traumatic loss of a girlfriend brought him out of a 14-year hiatus from graffiti writing. He has since been caught three times spraying his tag on property, each time while walking a friend’s dog.

“Everywhere that dog stopped to pee I would write my name,” Ortiz says. “The streets were like my canvases. I just started writing my name everywhere.”

When a pair of police officers smelled the fresh paint and nabbed Ortiz, they asked whether he saw himself as too old to be doing graffiti. But even now, Ortiz keeps a spray can or marker in his pocket to satisfy that incessant itch to tag mailboxes, signs and fire hydrants.

Graffiti documentarian and photographer Henry Chalfant looks back at Ortiz’s heyday as a revolutionary time period in street art. “The culture is gone really,” Chalfant says. “The culture that was alive in the ’70s and ’80s doesn’t exist anymore.”

Chalfant says change came when the Metropolitan Transportation Authority took over the New York regional train system and manufacturers started to build paint-resistant trains. Police also aggressively cracked down on graffiti in the ’80s and ’90s.

Ortiz now spends his days painting, peddling his art to galleries and buyers. He never quite rose to the level of fame as some of his graffiti counterparts, and the appetite for graffiti art has diminished in the U.S. art world.

Witten’s brush with fame now often comes with his freelance art writing and his sporadic visits to his daughter’s school, where he teaches her classmates how to draw. Lulu knows her father draws “crazy art,” a term she picked up from seeing graffiti on trains.

From time to time, the thought of spending a few hours in a deserted freight yard still crosses Witten’s mind. Taking into consideration his daughter, he won’t admit whether he still train-bombs. But he won’t say he doesn’t, either.

“I’ll decide when I’m too old,” he says. “Fortunately, there’s no forced retirement in graffiti.”