Julie Patz, mother of Etan Patz, speaks on NBC-TV's "Today"...

Julie Patz, mother of Etan Patz, speaks on NBC-TV's "Today" show in New York City on March 26, 1981. Credit: AP

New York police and FBI agents investigating one of the nation's most baffling missing-persons cases began digging in a SoHo basement Thursday, looking for the remains of Etan Patz, a 6-year-old boy who disappeared on his way to school in 1979.

Detectives and federal investigators cordoned off a building at 127 Prince St., at the corner with Wooster Street, after cadaver dogs a few weeks ago picked up trace scents of human decomposition at the location, a law enforcement official said.

The case, which has frustrated officials for more than three decades, was reopened in 2010 as Manhattan District Attorney Cyrus Vance Jr.'s investigators began re-examining old leads.

The Prince Street building had been one of a number of locations looked at earlier in the search for Etan, but had not been fully explored until now, the law enforcement official said.

The building is about a block from where the boy lived with his parents before he disappeared on May 25, 1979.

A legal source familiar with the Patz investigation and another law enforcement source, who spoke on condition of anonymity, said a carpenter who was friendly with Etan's family worked there at the time. Etan had visited the wood shop the day before he disappeared on the way from home to school, the law enforcement source said.

The carpenter was known to investigators at the early stage of the missing child case, but not considered a suspect, that source said. But after new information surfaced, investigators focused on his former workplace.

The law enforcement source added that authorities believe the 13-foot-by-62-foot basement area they are searching was "sealed off" with fresh concrete around the time of Etan's disappearance.

The building superintendent, Stephen Kuzma, 78, said FBI agents showed up a couple of weeks ago and asked to examine the basement. "They told me it was something about Etan Patz," Kuzma said. "They said they had reopened the case. They came three times. The third time they had the dog with them. The dog sniffed around the boiler room."

Investigators started the dig after Vance's staff secured a search warrant from a Manhattan State Supreme Court justice.

NYPD spokesman Paul Browne said the search, expected to last five days, involves tearing down walls and breaking through a layer of concrete before the ground is exposed for excavation. The building is now the site of boutiques and residences.

A woman who answered a phone number listed to Stanley Patz, Etan's father, declined to comment.

The Patz case is one of the most well-known missing child cases in U.S. history and sparked a national movement to publicize the plight of missing children. Etan was the first to have his picture appear on the side of a milk carton and his case also turned May 25 into National Missing Children's Day.

The case eventually led to the formation of the National Center for Missing and Exploited Children.

The Patz case has been largely dormant since 2004, when a Manhattan judge ruled that a Pennsylvania inmate named Jose Antonio Ramos was responsible for the abduction and presumed death of the boy. That came after Ramos, who was never criminally accused in Patz's death, ignored orders to answer deposition questions for a lawyer representing parents Stanley and Julia Patz.

Ramos, 68, was the boyfriend of Etan's baby-sitter, authorities said, and the former mental patient was later convicted in a sex-abuse case involving an 8-year-old boy in Pennsylvania, where he is serving up to 27 years and due to be released in November.

With Igor Kossov, John Valenti and Maria Alvarez

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