For many years Stanley Patz has marked two anniversaries with a heartbreaking ritual. On Oct. 9, his son Etan's birthday, and May 25, the day in 1979 that the 6-year-old vanished from a Manhattan street, the grieving father sends a copy of Etan's missing-person poster to Jose Antonio Ramos—the jailed pedophile he believes killed the child. "And I type on the back," said Patz, 58, earlier this year, " 'What have you done with my little boy?' "

This year Patz did something even more wrenching. On Nov. 15 he signed a petition asking that Etan be declared legally dead. "It is more painful than most people can understand," says Patz. But it clears the way for him and Etan's mother, Julie, 57, to bring a wrongful-death lawsuit against Ramos, who is suspected of having abducted and murdered Etan in one of the most publicized missing-child cases since the 1932 Lindbergh kidnapping.

Ramos, now 57 and serving 13½ to 27 years in Pennsylvania for molesting two boys, was at the time the friend of a woman who sometimes walked Etan to his bus. Though one of Etan's parents usually took him, they were busy on May 25, 1979, and let the first grader walk the two blocks alone.

Although Ramos was arrested as early as 1982 for trying to lure away two boys, it wasn't until six years later that he admitted having taken Etan to his apartment and making sexual advances—but he denied murdering him. Then, in the early '90s, a pair of inmates told then-federal prosecutor Stuart GraBois that Ramos had bragged of abusing and killing Etan before disposing of his body in a manner Ramos said was "too horrible" to describe.

This summer police searched Ramos's old building but found no DNA evidence. With chances dimming for a prosecution of Ramos—denied parole in June but eligible again in 2003—the Patzes (who have two other children, now grown) decided to sue. "This is a way of letting the world know who was responsible," says GraBois, "to put some finality on this terrible tragedy."