Etan Patz Inquiry Returns to a Prince Street Basement and an Old Handyman A jackhammer lay outside 127B Prince Street as investigators looked for evidence. Investigators looking into the disappearance of Etan Patz began focusing recently on a handyman after a review of old case files showed that a concrete floor in a building in SoHo where he once had a workshop - and that was on the route Etan took when he disappeared - had looked uneven or was not all the same color, a person briefed on the case said on Friday. The explanation the handyman, Othniel Miller, gave shortly after Etan disappeared 33 years ago - that work had been done beneath the floor - led investigators to conduct a new round of interviews in recent weeks that led to the search and excavation of Mr. Miller's old work space this week, the person said. Mr. Miller was not initially a suspect, the person said, in part because he told investigators that he had not been in SoHo the morning of May 25, 1979, when Etan vanished while walking from his home to a school bus stop. "He said he wasn't there; he had some sort of alibi, and it sort of checked out," said the person, who spoke on the condition of anonymity because the investigation was continuing. That alibi was supported in part by a coworker, the person said. On Friday, Mr. Miller, 75, hired a criminal defense lawyer who, after meeting with Mr. Miller and his relatives for more than an hour, said that his client had had nothing to do with Etan's disappearance. The lawyer, Michael C. Farkas, said his client did not deserve the scrutiny brought on by his long-ago connection to the basement of the building that investigators began searching on Thursday. "He had no involvement with what happened to this beautiful young boy," Mr. Farkas said. Mr. Miller has cooperated with this investigation for over 30 years, and he will continue to cooperate to the best of his ability. Mr. Farkas, who said he had not yet spoken with investigators, added: "We do not know at this time why he is now a suspect as opposed to sometime in the past." After Etan disappeared, investigators focused on a pedophile, Jose A. Ramos, who has been the prime suspect since then, although he has never been charged. He is currently imprisoned for another crime. At the site of Mr. Miller's old workshop, a phalanx of investigators, utility workers and others continued a painstaking excavation of the 806-square-foot basement below 127B Prince Street, at the corner of Wooster Street, just half a block west of the loft where Etan lived 33 years ago, and where his parents, Stan and Julie, still reside. Using jackhammers and pickaxes, they split the 13-by-62-foot space into quadrants and began their work along the northern wall, breaking up separate sections of poured concrete flooring, between two and six inches thick, spread over a relatively flat area of dirt, officials said. Outfitted in ear muffs, dust masks, safety glasses and gloves, agents from a Federal Bureau of Investigation evidence response team and New York City police officers formed a bucket brigade, handing larger chunks of concrete along an assembly line leading out of the basement, upstairs and into a large garbage bin on the street. Smaller chunks of broken concrete and debris were put in pails and passed along in the same way, officials said. The investigators also planned to dig down four or five feet into the earth, or until it appeared undisturbed; shine sophisticated X-ray machines onto the cinder-block walls of the basement; and spray the area with a chemical that could expose bloodstains or other aberrations. Cyrus R. Vance Jr., the Manhattan district attorney, reopened the case in 2010, and the SoHo excavation represents the most extensive effort since then to find clues. But Police Commissioner Raymond W. Kelly warned against expecting a quick solution. "I think what it indicates is that a lot of careful work is going to be done," Mr. Kelly said after an event at 1 Police Plaza on Friday. Precise, detailed, deliberative work is going to be done, as opposed to characterizing it as being something that should lead to optimism. Stephen Kuzma, 78, the manager of the building on Prince Street, said he had lived on the fourth floor since the 1970s and recalled Mr. Miller pouring cement for a new bathroom on his floor as well as doing work in the basement. But he did not remember when that work was done. Joseph Goldstein, Randy Leonard and Christopher Maag contributed reporting.