Police say the teen was charged, but due to her age, her identity will not be released.
Officials say the suspect mugged a 24-year-old of her cell phone before the victim's doorman jumped in to help.
Thanks to the doorman, the victim was unharmed, and she still had her purse even though the suspect and one other person managed to snatch her phone.
"I did what I could, and I wish I could have done more, but it just happened so fast that I couldn't," said the doorman, who asked to remain anonymous.
The attack happened around 3:45 p.m. just outside of an apartment building at 75th and Madison.
In a matter of seconds, the pair of thieves chasing the 24-year-old woman pinned her up against the glass of the building lobby, right in front of the doorman at his post.
"I heard like a thump. She hit the glass with her face. And when I looked up our eyes kind of met and all she said, 'Help,'" said the doorman.
When he ran outside to help, the attacker who had pinned the victim yelled, "She stole my phone," the doorman said.
"So, I stepped back because now I thought, I am aiding the thief? But that was enough for them. That little distraction," the doorman said.
Then, the male assailant grabbed the victim's phone and ran, as the victim tried to chase him.
The doorman says the two thieves were laughing as they ran away with the phone.
2 suspects wanted for robbing woman on UES before doorman intervened
"What struck me is that they were so bold. Even when I was outside, they still continued to rob her," the doorman said.
Witnesses who saw the whole attack did nothing.
Residents of the building at 75th and Madison are praising their doorman, calling him a hero for his quick intervention in a violent, brazen robbery.
ALSO READ | School employees at New Jersey high school save sophomore when his heart stops beating
School staff rush in to save student whose heart stops beating
----------
* Get Eyewitness News Delivered
* More Manhattan news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube