NEW YORK (CBSNewYork/AP) — More than three decades after the disappearance of Etan Patz, the man accused in the 1979 disappearance and death of the 6-year-old boy is now on trial.

A standing-room only crowd packed the courtroom as opening statements began Friday in the trial against Pedro Hernandez, a man who worked in a nearby bodega at the time and confessed to killing the boy many years later.

READ MORE: Pekingese Named Wasabi Crowned Best In Show At Westminster

In her opening statement, Manhattan Assistant District Attorney Joan Illuzzi-Orbon said Etan was a “tiny man with a big heart” who couldn’t wait to walk to his school bus stop alone.

She said his “beautiful, little life” was snuffed out the very day he achieved that childhood freedom in 1979, calling the case “a crime that changed the face of this city forever.”

Both Hernandez and Etan’s father, Stan Patz, sat stock-still as the prosecutor spoke. Hernandez’ wife, Rosemary, was also in the courtroom.

Hernandez emerged as a suspect in 2012 based on a tip and a videotaped confession that prosecutors say was foreshadowed by remarks he made to friends and relatives in the 1980s.

“You will see and hear his chilling confession,” Illuzzi-Orbon told jurors. “What you will see is someone who very keenly controls the information that he puts out.”

The defense depends on convincing jurors his confession was false and suggesting that the real killer may be a convicted Pennsylvania child molester who had been a prime suspect for years.

In his opening statements, defense attorney Harvey Fishbein said Hernandez “cannot distinguish between what is real and what is not.”

Fishbein urged jurors to focus on what he called a lack of evidence against his client. Hernandez has pleaded not guilty.

Etan disappeared while walking to his school bus stop May 25, 1979. He was never found, but was legally declared dead as the investigation spanned decades.

Prosecutors have spotlighted Hernandez’s videotaped, hours-long confessions, in which he says he offered Etan a soda to entice him into the basement of the Manhattan convenience store where Hernandez worked.

Then, Hernandez said, he choked the boy and dumped him, still alive, in a box with some curbside trash.

READ MORE: Luna Found Safe After Carjacking In Brooklyn, Family Says

“Something just took over me, and I was just choking him,” said Hernandez, 54, of Maple Shade, New Jersey. “He just kind of stood there and I just felt bad, what I did.”

Defense lawyers say Hernandez’ confession is fiction, dreamed up by a mentally ill man with a low IQ and a history of hallucinations and fueled by over six hours of police questioning before Hernandez was read his rights.

After confessing, Hernandez told a defense psychologist his memory of the killing “feels like a dream” and he wasn’t sure it had really happened.

A defense psychologist wrote that Hernandez’s psychological problems and intellectual limitations make him more likely than other people to confess falsely.

Hernandez’s lawyers also plan to point to longtime suspect Jose Ramos, a Pennsylvania prisoner who dated a woman who sometimes cared for Etan.

Authorities said Ramos made incriminating statements when questioned about Etan in the 1980s, though he never confessed to killing the boy.

Ramos has denied it, but a civil court found him liable for Etan’s death in 2004 after Ramos stopped cooperating with questioning.

The trial is expected to last up to three months and feature witnesses including Etan’s mother Julie, psychologists, an inmate informant who knows Hernandez and possibly other informants testifying against the earlier suspect.

Etan’s mother will only be in the courtroom once, and that will be to testify, CBS2’s Jessica Schneider reported.

Etan’s disappearance ushered in a new protectiveness into American parenting.

He became one of the first missing children featured on milk cartons. His parents advocated for legislation that created a nationwide law-enforcement framework to address such cases.

The anniversary of his disappearance is now National Missing Children’s Day.

MORE NEWS: Police: Subway Passenger Stabbed, Robbed On A Train In Queens

(TM and © Copyright 2015 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2015 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)