The disappearance of Etan Patz touched off an epic investigation and transformed how parents across America watch over their children. NY1's Michael Scotto filed the following report.

From the day Etan Patz vanished, his parents searched for the 6-year-old boy and police combed through tips. But his remains were never found, and for decades, the investigation went nowhere.

"There were no clues. There was no crime scene. There was no apparent crime scene for decades. There were no witnesses. There was no body," said Lisa Cohen, who teaches at Columbia University and has written extensively about the case. 

In 1989, police narrowed in on Jose Ramos, a convicted child molester who was friends with Etan's babysitter.

A decade later, a search of an apartment where he had lived came up empty.

But seven years ago, the new Manhattan district attorney, Cy Vance, vowed to solve the mystery. 

"They had the courage to say, 'We will go through this again, and we will be there while you reinvestigate this case,'" said Karen Friedman Agnifilo of the Manhattan district attorney's office.

A search of a SoHo basement led to another dead end.

But news reports of that search caught the attention of Pedro Hernandez's family. They told police that Hernandez, once a bodega worker in Etan's neighborhood, had confessed to killing him. 

Two years ago, Hernandez's first trial ended with a hung jury.

Some of those jurors watched the second trial and said prosecutors did a better job attacking the defense claim that Hernandez was delusional.. 

"We believe they were very thorough in the mental illness case that the defense brought, showing that he was not mentally ill or delusional," said former juror Jennifer O'Connor. 

The conviction puts to rest a painful chapter for the city, one that ultimately changed how parents watch over their kids.  

"Before Etan, people let their children roam free. They would see them at dinnertime. After Etan, people watched their children like hawks," Cohen said.

Posters of Etan were placed across the city, and his picture even appeared on milk cartons - changing how missing persons cases are pursued.

Eventually, the city moved on, but those involved in the case never let go - including jurors from the first trial, who sat through the second.  

"It was a therapeutic moment when we heard the guilty verdict," O'Connor said. "There was a lot of squeezing and tears and breathing. Relief."