A security camera was silently recording, as a predator sized up his prey; in this case a 17-year-old girl.
Brandishing a knife, he dragged her off the elevator and into a stairwell where he tried to attack.
"That shows that we are not safe around here, you know?" resident Linda Morales said.
The man did not succeed.
His victim managed to fight him off and he disappeared down the stairs.
But police say it's the second time he's targeted a young women in the LaGuardia Houses in the past 16 months.
In January of 2010, they say the same man sexually assaulted a 19-year-old woman, in another building across the courtyard.
It's where longtime resident Jessica Rodriguez lives with her 20-year-old daughter.
"I pray to God they catch him. I really do because that's disgusting," Rodriguez said.
On Saturday, police canvassed the complex for leads in the case.
They say the suspect is between 17 and 25 in age, approximately 5'8" to 5'10" and heavyset.
In the first incident, he wore a black North Face jacket, blue jeans and black boots.
In the second, a gray hooded sweatshirt.
"It's very scary because I come home late sometimes and that scares me a lot," resident Evelyn Conde said.
Conde says it could be a stroke of luck that Thursday's attack happened in the building it did.
She says most of the other buildings in the complex do not have working security cameras.
She lives in one of them and feels anything but safe.
"We've been fighting for it because we want cameras. I want cameras in the building," Conde said.
Anyone with information in regards to this incident is asked to call Crime stoppers at 1-800-577-TIPS (8477).