(CNN) -- Police are still searching for an autistic teen that has been missing since he was last seen on video running out of his Long Island City, New York, school three days ago.
Surveillance video shows 14-year-old Avonte Oquendo of Queens running out the door of Center Boulevard School in Long Island City at 12:38 p.m. Friday. Police say Oquendo is autistic and cannot verbally communicate.
"It's been heartbreaking. I just need to find my son because he needs his family, he cannot fend for himself out there," Avonte's tearful mother Vanessa Fontaine told CNN affiliate WABC.
"This is just the hardest thing to have your child disappear, and you cannot bring him home with you," Fontaine said.
According to the surveillance video provided by the NYPD, no supervisor or monitor stopped him when he ran out.
"He is supposed to have one-to-one supervision at all times," Fontaine said through bouts of tears. "He has the mental capacity of a 7- or 8-year-old."
The New York City Department of Education issued a statement saying, "We are working closely with police who are conducting an active investigation."
The school is not commenting.
Police say Oquendo was last seen wearing a gray striped shirt, black jeans and black sneakers. He is 5 feet, three inches tall and weighs 125 pounds.
Missing posters are being handed out and the surrounding areas are under investigation, WABC reported.
"He doesn't know that, you know, 'I can get hurt in the street, someone can grab me and take me.' He doesn't know that," Fontaine said Monday. "He doesn't know fear."
Anyone with information was asked to contact the NYPD's Crime Stoppers Hotline at 800-577-TIPS. The public can also submit tips at Crime Stoppers website, nypdcrimestoppers.com or text to 274637(CRIMES), then enter TIP577.