In that time there have been false hopes, police sweeps and increasingly frantic pleas from the boy’s family. Still, as of Thursday afternoon, he remained missing.
The search has been complicated by the fact that Avonte has a severe form of autism, unable to verbally communicate and unable to care for himself.
Whatever Avonte was thinking as he left the Riverview School, at 1-50 51st Avenue, last Friday would have remained locked inside his own mind, even if he had come across someone looking to help.
Beyond the surveillance video, the police have had few clues to help guide the search.
Avonte’s family said he liked trains, so the police have been focusing on nearby subway stations, posting fliers throughout the system and canvassing platforms for witnesses.
On Monday, after a statewide missing-child alert was issued for him, power to the No. 7 line between Grand Central Terminal and Vernon-Jackson Avenues stop in Long Island City was cut briefly as workers searched the tracks. Later, power to the G line was suspended for a short time for a similar sweep.
On Monday night, there was a promising tip that Avonte had been spotted near a diner in Astoria, Queens.
The police commissioner, Raymond W. Kelly, told reporters that bloodhounds had been deployed there to try to pick up the boy’s scent, but the tip did not pan out.
The school is near the East River, so the police deployed boats to look up and down the shoreline.
On Tuesday, the police thought they had found the boy in East Harlem. But it was not Avonte.
“A few of us got there to the hospital and realized it’s not him,” his brother, Daniel Oquendo, told reporters at the time. “It hurts because you do want things to end, but somebody’s child was found — just not ours — but we’ll continue to pray and look.”
Daniel Oquendo has been reaching out for help on social media, including Twitter, using the name KingDetrick.
Avonte was last seen wearing a gray striped shirt, black jeans and black sneakers. He is 5-foot-3 and weighs 125 pounds.
Anyone with information was asked to contact the Police Department’s Crime Stoppers hot line at (800) 577-TIPS.
Avonte’s family, while not giving up hope, is also asking how he could have eluded adult supervision to leave the school. He was in special education classes, which have additional adult supervisors to deal with the unique needs of the students.
On Wednesday, David H. Perecman, the family’s lawyer, filed a claim against the city, alleging negligence, the first step toward filing a lawsuit against the city and the school.
Officials from the Education Department referred all questions to the police.
Mr. Perecman said it took the school an hour to contact the family after Avonte left the building around 12:45 p.m.
He said that when Avonte’s grandmother arrived at the school two hours after he disappeared, officials were looking at the video for the first time.
“When a child disappears from the school, it could not have been too long before they notice this child is missing,” he said.
For now, Mr. Perecman said, the family is focused on trying to bring attention to the case, hoping it will lead to tips that, in turn, bring Avonte back home.