It was a crime in progress. A young man in a hooded sweatshirt and jeans sat on a gleaming subway seat, his face focused on the train window as he scratched something into the glass.
On Monday at 1 p.m. on a northbound N train, near the subway station at 30th Avenue in Astoria, Queens, an alert rider took out a cellphone and snapped a photograph of the young man, along with another image of him sitting slightly forward in his seat, the police said.
The commuter turned over the photos to the Crime Stoppers hot line, a relatively new innovation in reporting crime.
The images were scrutinized by the Police Department’s vandalism task force, which managed to identify the young man as Andrew Morello, 18, who officials said was already known to investigators as a “tagger.” He had been arrested in March on a graffiti charge after spray-painting the word “Shelly” on a parked commercial vehicle in Queens, according to court records.
On Friday, officers went to his house at 48-04 20th Avenue in East Elmhurst, and arrested him. (He struggled while he was being handcuffed, and one of the arresting officers was treated at a hospital for a wrist injury, the police said.)
Mr. Morello faces charges of criminal mischief, making graffiti, resisting arrest and possession of graffiti instruments, the police said.
With cellphone cameras in the hands of thousands of potential witnesses, the changing face of law enforcement knows no bounds.
Mr. Morello was arrested for “scratchitti,” according to the police, caught in the act of scratching graffiti onto glass.
Over the summer, Police Commissioner Raymond W. Kelly announced at police headquarters that citizens should supplement their 911 calls with cellphone pictures. The department has also encouraged citizens to send in tips messages with photographs and by text messages to the police.
It was not the first time that the cellphone camera has yielded an arrest. Shortly after Mr. Kelly made his announcement, a bicyclist was knocked over by a truck. The bicyclist took a photograph of the license plate. The driver was eventually arrested, the police said earlier.