No body was found, no arrests were made, and no credible sightings have been reported in the 50 years since Jill Jones, who was not yet 3, came home alone. She carried a plastic potted poinsettia she couldn't explain and told her mother "the bogeyman" took Billy.
A neighbor had seen Billy about 11:45 a.m. and suggested he go home. His mother, who had been busy with her infant son, answered a knock at the door at 1 and found only Jill.
"Somebody has to know something. I really do believe that," says retired Vineland Police Sgt. Patrick Dougherty, 62, who remembers the case from his childhood. "Until I see a body, I'm not going to rule out that he's alive."
Under hypnosis in the 1980s, Jones - who now lives in Gloucester County - gave a vivid account of holding hands with Billy as two men fought in front of an oil-drum fire at the Palace of Depression, a quirky local landmark not far from the family's home.
"I remember running, and eventually I could see the door to my house," says Jones, a grandmother of four whose life has been haunted by this mystery.
Her parents, now long deceased, had a rough time accepting their oldest child's death, and they moved the family out of the city not long afterward. Jones says she still dreams about Billy.
"It's like he's on the other side of a brick wall, and he's calling me, and I have to find a way to get to him," she says. "I still say I'm going to find him."
At the time of Billy's disappearance, searchers combed the Palace, a faded tourist attraction built from discarded materials by a local eccentric. "It was thought that he might have wandered in there," Vineland Detective Kristian Kirchner says.
He joins Jones and me at her home, where she places several boxes of clippings and photos of Vineland's best-known unsolved case on the dining room table.
In recent years information about Billy's disappearance has been entered into the National Crime Information Center system. On the 50th anniversary, the FBI uploaded photos of the missing boy as well as an "age-progression" image of him onto the agency's website ( www.philly.com/missing).
"In 2009 we really started to look at the case again," says Kirchner, who grew up in Vineland and became a cop in 1998. "Obviously there have been huge technological advances since 1962."
Jones has provided a DNA sample. Separately, investigators have determined that the poinsettia, much discussed over the years, does not appear to have a significant role in the case.
They have talked to area residents and others about their memories of that day. Some of the conversations "have given us some information to look at from different angles," Kirchner says.
"We've also sat down with some of the original officers."
The police department hopes fresh exposure of the case beyond Vineland will result in new information.
"If Billy had been kidnapped, he very easily might have been taken out of the area," Kirchner notes. "In 1962, records were different, and it was easier to create a new identity for a 3-year-old."
"We want to talk to anyone who may have been in that area, who think they may remember something," says Police Lt. Matthew Finley.
"At this point nothing is insignificant. One clue could open a variety of doors, and you never know where those doors might lead."
Jones occasionally sees Billy in the face of a stranger and has been tempted to ask if the man has a giraffe-shaped scar.
"I have faith" Billy is alive, she says. "I'll never give up."
Jones had to leave her big brother behind during that nightmarish scene at the Palace of Depression.
But as long as she's alive, she'll never let go of his hand.
Anyone with information about Billy Jones' disappearance is asked to call the Vineland Police Department at 856-691-4111.
Contact Kevin Riordan at 856-779-3845 or firstname.lastname@example.org, or follow on Twitter @inqkriordan. Read the Metro columnists' blog, "Blinq," at www.phillynews.com/blinq.