Ms. Rivera said Mr. Hernandez approached her after a prayer meeting in 1982 at her house. She testified Mr. Hernandez became emotional and let on “something terrible” had once happened. A “muchacho” had approached him, he said, using the Spanish word that can refer to either a child or a young man. He said “he had felt violated,” by which she took him to mean there had been a robbery attempt.

“He said it had gotten out of hand and it ended up that he had put his hands around the person’s neck and he had strangled him,” said Ms. Rivera, who was married to Mr. Hernandez for a year and a half in the mid-1980s. Mr. Hernandez told her he had thrown the body in a Dumpster and covered it with plastic bags, she said.

Later, after they married, Ms. Rivera found a picture of Etan in a shoe box of Mr. Hernandez’s belongings, she testified. The picture, which appeared to have been cut from a lost-child poster, showed Etan wearing an Eastern Airlines cap.

When she confronted Mr. Hernandez about it, he became nervous, she said. “He explained to me that that child had disappeared within the area where he worked in New York City,” she said. He then said he was familiar with the Patz family and knew they lived near the bodega where he worked.