It was a New York City case that gripped all of America. When 6-year-old Etan Patz vanished while walking to his school bus in May of 1979, parents throughout the country could no longer trust that their children were safe.

Former federal investigator Stuart GraBois remembers Etan's disappearance as if it happened yesterday.

"I think prior to that time, people were just not aware. There was an age of innocence that all of a sudden disappeared," he said.

Family attorney Brian O'Dwyer agrees. "My son was born a few months after Etan was taken off the street," he says. "From that moment on, my wife never left him out of our sight, and that occurred with almost every parent in New York and continues to this day."

Etan became the poster child for missing children, the first angelic smile to be plastered on milk cartons, his disappearance triggering a massive worldwide search. Prosecutors traveled as far as Israel to follow leads.

Now, 22 years later, Etan is back in the headlines again, because of his parents' determination to have someone charged with killing him.

Etan had been begging his mother to let him walk the two blocks from their apartment in downtown Manhattan to his school bus stop, alone. On May 25, 1979, Julie Patz finally said OK. It was the last time she ever saw her son.

5 years went by before GraBois got the case. "I had been assigned to the case by (then federal prosecutor) Rudy Giuliani, and his marching orders were: 'Do whatever you can, and you'll have our full support.'"

GraBois quickly focused his attention on a known pedophile, Jose Antonio Ramos, who may have befriended Etan's baby-sitter to get near the boy.

"It's all speculation of course, but we believe that he (Ramos) got close to him (Etan) ... ultimately brought him back to his apartment, and disposed of him," GraBois says.

There was not enough evidence to prosecute, but GraBois continued to pursue Ramos. He prosecuted him in another case in Pennsylvania, where Ramos pleaded guilty to molesting a young boy. Ramos is now serving a 10-20 year sentence for that crime, and as he does, there's word he's been talking about Etan.

"We have informant testimony that we are going to present that Jose Antonio Ramos made admissions to a jailhouse informant that Etan is dead and that they will never find the body," says O'Dwyer, who hopes Etan's parents can use an alleged jailhouse confession against Ramos in civil court.

On Tuesday, Etan's father, Stanley, asked a judge to declare his son officially deceased, so that he and his ex-wife can charge Ramos with the boy's wrongful death.

O'Dwyer hopes a civil case will succeed where a criminal case has not. "The burden of proof is much less," he says. "In a civil case you have to have the preponderance of the evidence. In other words, it's more likely than not that the case is made."

Investigators and lawyers agree that Ramos should be held accountable. GraBois is now the spokesperson for Julie and Stanley Patz, who are still too distraught to talk to the press. He says the parents, more than anything, want "accountability, to say to Ramos, you did it. You're responsible. Look what you did to our son."

Ramos may or may not respond to the civil suit. If he does, prosecutors look forward to interviewing him, perhaps gaining new clues that can help the criminal case. If he does not respond, a judgment will stand against him, which may help to keep him behind bars when he comes up for parole in 2014 — and perhaps bring a measure of consolation to a couple of parents, and a nation, who have been grieving for 22 years.