She was 14 and alone when she was last seen, in her flowery blue blouse, stepping off a bus in downtown Mount Holly one late June day.
Scrawled notes left behind at her home in neighboring Burlington City detailed her plans to meet up with a stranger in a red Volkswagen who would take her to his Mount Holly home to babysit his 5-year-old son.
That was 43 years ago. Margaret Ellen Fox disappeared.
Police and FBI agents have long believed Fox was murdered after her rendezvous with this mystery man, who was never located.
But what really happened?
A retired Willingboro police detective who is reviving the cold case has a different theory.
"Is she alive? I hope so. Maybe she felt she wanted a new life," Michael Dalesio suggested in a recent interview. "But how could she fall off the grid like that for so long?"
In the hopes of solving Burlington County's coldest missing-persons case, Dalesio is poring through two boxes of investigative files and is revealing intriguing details that previously were not disclosed. Among them is a confusing $10,000 ransom note sent to Fox's parents that mysteriously mentioned the Symbionese Liberation Army. This was four months after Patty Hearst was abducted by the SLA.
Then there were also Fox's diaries, found in her bedroom, which included passages about being bullied in school, about snowballs being hurled at her, and about her wish to move to California or Florida to start a new life.
Along the way, suspects came and went.
In an NBC News 10 broadcast last month, Dalesio launched an appeal to the public. "Maybe somebody remembers something and has not come forward before," he said.
Already, he has received two tips that hint she may be living out of state. A rendering created by the National Center for Missing and Exploited Children shows how she might look today, at age 57.
Dalesio, 53, was looking for something to occupy his time and energy after he became disabled a few years ago when he and several officers were involved in a scuffle with a man who was being taken to a psychiatric facility. Dalesio's right foot was crushed and he had to have his ankle replaced.
"I felt my career was cut short," he said, adding that he had been a police officer for 21 years, including 14 as a detective. He is doing this review as a volunteer.
"This is a case that still claws at investigators," Dalesio said. He said that she likely was killed, but there's a possibility that she was not, and that needs to be explored.
Dalesio said Fox's parents have both died, but two of her brothers are alive. Neither could be reached for comment.
More than 1,100 people are on New Jersey's missing-persons list, dating to 1969, according to state police.
Leonard Burr, a retired Burlington City detective who was the first officer sent to investigate when Fox went missing June 24, 1974, said it was his only case that he had not solved. "It hung with me for a long time," said Burr, now 80. He interviewed the bus driver, passengers, and owners of the shops at the bus stop near the intersection of High and Mill. One passenger watched her get off, but no one else had any other information on Fox or the VW.
"It was a very frustrating case, I could get nothing," he said. "Whooosh, she just disappeared."
Burr suggested there was foul play, but said one of the new tips that recently came in said someone had seen a person who fits Fox's description. "If that's the case, then who knows? Maybe she just decided she liked her freedom and went off," he said.
Back then, Burr said, there was rivalry between the local police and the FBI, and the lack of cooperation could have hurt the investigation. "The goal now is to solve a case, not get credit," he said.
Dalesio began reviewing the Fox file in April, and in a recent interview chronicled the ins and outs of the case over the years and sprinkled in ideas of what could be analyzed further. "We need to close the case. There has to be an ending or a conclusion… Even if she just moved away, this brings hope to people to know they won't be forgotten," he said.
Fox was in eighth grade at St. Paul's Roman Catholic School in Burlington when she and a cousin, Lynn Parks, placed a classified ad in a local newspaper, with a phone number, seeking babysitting work. A man who identified himself as John Marshall responded. He told Parks he had a 5-year-old son, a backyard swimming pool, and a swing set at his Mount Holly home.
Parks' parents wouldn't give her permission to go, so she gave Fox the man's number and phone number. When Fox called him, he said he would pay her $40 to babysit the child for four hours a day, five days a week, and that he would meet her at the bus stop on June 24.
Four days later, her parents received a phone call from a man who claimed he had the teenager and was seeking $10,000. A day later, a note arrived at the Fox home saying the money should be put in a box "with blue wrapping (same as Margaret's blouse)… Margaret is alright. We only tore her blouse and broke her glasses. Follow the instructions …"
Dalesio said the note could have been a hoax. Fingerprints were retrieved from the note by the FBI and he hopes to locate them and place them into a national database to see if they can find a match. Back then, the prints were only matched up against local collections, he said.
The phone number that was noted on Fox's notes with John Marshall's name was traced to a phone booth at a former supermarket in Mount Holly where the manager was named Jack Marshall. But he had an alibi and a polygraph determined he was truthful.
Four years later, a sex offender in Mount Holly came to the attention of the police and FBI. The suspect had owned a red Volkswagen at the time Fox went missing, and lived in Mount Holly not far from the bus stop. But he also had an alibi – he was a ham radio operator and a logbook he kept over the years showed he had been on the radio with someone at the time she got off the bus.
Dalesio said he believes the case can still be solved. "We're going to look at everything," he said.