Julie Patz, on the Today show, two years after her son Etan's disappearance.

A New York grand jury has indicted Pedro Hernandez in connection with the 1979 death of Etan Patz. Mr. Hernandez, a 51-year-old resident of Maple Shade, N.J., has been charged with murder in the second degree. He was arrested in May 2012 after reportedly confessing to killing the little boy.

Etan Patz was on his way to school when he vanished from Soho on May 25, 1979. His disappearance became national news, his image eventually appearing on milk cartons across the country.

At the time, Mr. Hernandez was a stock clerk at a bodega near the Patz residence. According to a statement from NYPD Commissioner Ray Kelly, Mr. Hernandez said he lured Etan into the basement of the bodega by promising the boy a soda.

The New York Post reports that some investigators don't believe the state can win its case against Mr. Hernandez, and they have good reasons:

Hernandez has been described by his defense lawyer as bipolar and suffering from auditory and visual hallucinations. A six-month investigation has yielded no additional evidence beyond Hernandez's four, original arrest confessions plus the word of six of Hernandez's church and family members, who have told cops that Hernandez made incriminating statements about having killed a child or "done something bad" in the past, according to sources.

Mentally stable or not, Mr. Hernandez may have been confessing to the crime since Etan Patz disappeared. Detectives investigating the case in 1979, however, dismissed those confessions as the ravings "of a lunatic" at the time.

Julie Patz, on the Today show, two years after her son Etan's disappearance.

In a press conference streamed live by multiple media outlets, N.Y.P.D. Commissioner Ray Kelly announced that police have arrested Pedro Hernandez in connection with the May 25, 1979 disappearance of Etan Patz. Mr. Kelly told reporters that police found "probable cause" to arrest Mr. Hernandez.

Mr. Kelly said Mr. Hernandez confessed to strangling and killing the boy as Etan headed to school the morning he vanished. Mr. Hernandez allegedly placed the body in a box which he left on the street.

Mr. Hernandez was a stock clerk in a bodega near the Patz home at the time of the disappearance. He allegedly led the boy into the basement there, luring him with the "promise of a soda," according to Commissioner Kelly.

A source tells The Daily Beast Mr. Hernandez may have confessed to Etan Patz's murder over 30 years ago :

Relatives of Pedro Hernandez first contacted police not long after Patz vanished from his New York City neighborhood on May 25, 1979, according to the source. The relatives are said to have told police after Patz’s disappearance that Hernandez, who worked in a nearby store, had admitted to them that he killed the 6-year-old boy.

Detectives interviewed Hernandez at that time, the source says, and he confessed to the crime. But the detectives deemed this first confession to be “the raving of a lunatic,” in part because he told them that he had put the body in a box and stashed it someplace only for it to disappear.

The same source told the Daily Beast that police simply didn't believe the confession, because "You can’t just leave a dead kid out in the street and nobody reports it."