An important detail has emerged in Pedro Hernandez's confession to the 1979 killing of six-year-old Etan Patz, but authorities are still struggling to provide physical evidence and a motive to substantiate Hernandez's story.

From The New York Times:

At first, Mr. Hernandez, 51, averted his eyes from the image of the 6-year old boy, who was last seen walking to school on May 25, 1979. But by the end of the interrogation, Mr. Hernandez had not only looked at the picture; he had also signed his name across it and even written a brief confession on the picture, one law enforcement official briefed on the investigation said.

Hernandez reportedly wrote "I killed him" or "I strangled him," across the photograph-- an interesting development considering previous reports had Hernandez claiming he'd never before seen the boy in the picture.

Cops also videotaped Hernandez's confession to the boy's murder.

Authorities searched Hernandez's Maple Shade, New Jersey home Wednesday and found "age appropriate" clothing from the 70s and a child's toy from around the same time, The New York Post reports. The items will be tested for DNA evidence. Cops wouldn't describe the clothing, and cautioned that Hernandez himself has a son, to whom the articles could also belong. Hernandez's hard drive was also confiscated during the search.

Investigators could have difficulty constructing a provable narrative with which to prosecute Hernandez. According to his confession, Hernandez put Etan's body in a platic bag which he then left on the side of the street. The bag was likely picked up by a sanitation truck and police say the body will probably never be found.

Additionally, Hernandez's motive for the crime remains a mystery. Hernandez did admit to being beaten as a child, The Times reports, but that could be too speculative a motive to hold up in court.

Hernandez's wife, Rosemary, doesn't believe her husband's confession, and cited his history of mental illness.

"Mrs. Hernandez has seen her husband's delusions and hallucinations and other mental illnesses for a very long period of time," Robert Gottlieb, the family's new high-profile lawyer, told CNN. "She does not believe the confession at all."

Hernandez is thought to suffer from schizophrenia and hallucinations. He is currently being held New York's Bellevue Hospital without bail. His next court date is June 25.