Pedro Hernandez, a former bodega stock clerk who confessed to luring 6-year-old Etan Patz into a basement and attacking him, was found guilty on Tuesday of murder and kidnapping, a long-awaited step toward closure in a case that bedeviled investigators for decades and changed forever the way parents watched over their children.

A Manhattan jury convicted Mr. Hernandez on the ninth day of deliberations after the second of two lengthy trials that brought renewed attention to Etan’s disappearance on May 25, 1979, as he walked to his school bus stop alone in SoHo for the first time.

The mystery of what happened to Etan shook New York and the nation, with photographs of the smiling, sandy-haired boy ubiquitous on milk cartons, “missing” posters, newspaper front pages and television newscasts. The alarm caused by the abduction reverberated across America, evoking the worst fears of parents and helping to change the way the authorities tracked missing children.

The vote to convict came after jurors returned to court Tuesday following a three-day weekend and watched — “for the 100th time,” one juror said — Mr. Hernandez’s recorded confessions. Around noon, the panel sent a note to the judge saying it had reached a verdict. Though jurors declined to discuss how their views had evolved while deliberating, they acknowledged overcoming significant divisions.