DEVELOPING: The New York City police commissioner said a person who's in custody has implicated himself in the disappearance and death of Etan Patz 33 years ago.

Commissioner Raymond Kelly said in a statement that further details would be released later Thursday.

The 6-year-old disappeared on May 25, 1979, while walking alone to a bus stop in Manhattan's SoHo neighborhood. The boy's photo was one of the first of a missing child to appear on a milk carton. 

The suspect was arrested in New Jersey on Wednesday and taken to New York City for questioning, Fox affiliate WNYW reported. 

The New York Daily News, citing sources, reported that the suspect is from New Jersey. He was known to investigators and is not a new figure in the case, law enforcement sources told WNYW. He worked and lived in the neighborhood where the boy disappeared.

The April excavation of a Manhattan basement yielded no obvious human remains and little forensic evidence that would help solve the mystery of what happened to Patz. The boy was officially declared dead in 2002.  

Authorities began ripping up the basement's concrete floor with jackhammers last month after a cadaver-sniffing dog had recently indicated the scent of human remains in the basement located steps away from the boy's home. 

The basement is the former workspace of retired handyman Othniel Miller, 75, of Brooklyn, N.Y., who was seen with Patz the night before he disappeared. Miller, whose workshop was on the route the boy would have taken to his bus stop, has denied any wrongdoing. 

Investigators have long focused their attention on Jose Ramos, a drifter and onetime boyfriend of Etan's baby sitter. In the early 1980s, he was arrested on theft charges, and had photos of other young, blond boys in his backpack. But there was no hard evidence linking Ramos to the crime.

Ramos, now 68, reportedly admitted trying to molest Etan on the day of his disappearance, but denied abducting him or killing him. Ramos has never been charged criminally in the Patz case and is currently serving a 20-year prison term in Pennsylvania for abusing an 8-year-old boy there. Ramos is scheduled to be released from prison in November.

The Patz family, who has remained in the same apartment for 33 years in the hopes their son would one day return home, has not commented on the recent developments. 

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The Associated Press contributed to this report.