Disappearance of six-year old Etan Patz drew national attention and puzzled police for three decades.

A man has confessed to strangling to death a boy who vanished on his way to school in 1979 New York police say.

Pedro Hernandez of Maple Shade, told police he choked Etan Patz to death and left his body in a bag in an alley, New York Police Commissioner Raymond Kelly told reporters

The disappearance of Etan Patz was a haunting case that terrified parents across America and baffled police for three decades that he instantly became a symbol for growing fears over the safety of children playing outside the home.

He was the first of many missing children to have his face pictured on milk cartons with an appeal for information. The date of his disappearance, May 25, became known as National Missing Children’s Day.

Thursday’s confession was a stunning breakthrough in a cold case that had defied the efforts of one of the country’s most sophisticated city police departments and ushered in the modern era of anxious parenting.

Kelly said Hernandez confessed for three hours, then accompanied New York Police Department detectives to the scene of the crime, which was a grocery store, or bodega, at the time, and which now sells eyeglasses.

He told investigators that he used “the promise of a soda” to lure away Patz, who was six and taking the school bus alone for the first time.

“He then led him into the basement of the bodega, choked him there and disposed of the body by placing him in a plastic bag and placing it in the trash.”

According to Kelly, Hernandez is married with a teenage daughter. He is a US citizen, with no criminal record, and has not previously been a suspect in the high-profile investigation. No motive has been established.

Police were led to the man by a tip that followed a sudden reactivation of the search, with police and FBI agents digging up a different basement in Manhattan last month.

“The individual came forward because of the recent notoriety of the case,” Kelly said.

Murderer remorseful

After evading the authorities for more than three decades, Hernandez apparently became guilt-ridden.

He “told family and others that he had ‘done a bad thing and killed a child in New York,'” Kelly said. Detectives who interviewed Hernandez thought “he was remorseful.”

The confessed murderer appeared “to think it was a feeling of relief,” Kelly said.

Hernandez was initially charged with second degree murder and now the Manhattan district attorney will decide how to proceed.

Patz’s parents have been informed, Kelly said, adding he hoped the development would “bring some measure of peace.” However, he did not expect that the remains of the boy would ever be found.

“It’s unlikely, very unlikely,” he said.

The original investigation gripped New York and the nation, with police searching around Patz’s home neighbourhood of SoHo in Manhattan and plastering “missing” posters showing the happy-faced boy with slightly gapped teeth and

straight, sandy-coloured hair.

Memories of the murder never entirely faded in New York and they were brought back abruptly during the intense search operation launched in a basement last month near the apartment in SoHo.

The search by teams of FBI and NYPD officers, conducted amid a huge media presence, ended with no announcements about any important discoveries, though debris from the excavation of the basement was removed for forensic analysis.

The longtime main suspect, a convicted child abuser named Jose Ramos, was never charged. He denied involvement.

At the time of the search last month, attention turned to another apparently false lead – a carpenter who had used the basement.