Heist, a car dealership bookkeeper, was going through an amicable divorce and had just been turned down for housing assistance. She left the half-done laundry, the defrosting dinner and her daughter and son, then 8 and 12 years old.
"Everybody that knew Brenda told us there was absolutely no way Brenda would leave her children," said Lititz Borough Police Detective John Schofield, who suspected for years she may have been killed.
"She explained to me that she just snapped," said Schofield, who met with her Monday in Florida. "She turned her back on her family, she turned her back on her friends, her co-workers."
He said she expressed shame and apologized for what she did to her family.
"She has a birth certificate and a death certificate, so she's got a long ways to make this right again," Schofield said. "She's got to take it slow with her family, I'm sure, and it's going to be a long process."
After she dropped off her children at school one day, Heist decided to join the three strangers as they hitchhiked for a month along Interstate 95 on their way to South Florida. She told Schofield she slept in tents and under bridges, survived by scavenging restaurant trash and panhandling, and kept her previous life a secret, contacting no one and using a pseudonym.
Now 54, Heist told police she spent seven years living with a man in a camper and working odd jobs, but more recently she was homeless again, living in a tent facility run by a social service agency.
"She said she was at the end of her rope, she was tired of running," Schofield said.
Her husband, Lee Heist, who was investigated and then cleared as a suspect, struggled to raise their children. By 2010, he was able to get the courts to declare her legally dead and collected on a life insurance policy. He has remarried.
Today, their daughter is a West Chester University sophomore, and their son recently graduated from the same college and is pursuing a career in law enforcement.
"They knew that I was there, and I loved them and would take care of them," Lee Heist told reporters.
He's angry because of the effect their mother's disappearance had on the children, but he also said he has forgiven her.
"There were people in the neighborhood who would not allow their children to play with my children" because he had been a suspect, he said.
Both his ex-wife and their children have expressed a desire to speak with one another, but for now they are taking things slowly.
People do sometimes "walk off," only to be found years later, said J. Todd Matthews, a spokesman for the National Missing & Unidentified Persons System, a Fort Worth, Texas-based organization with a database of about 85,000 missing people.
"It's not an everyday thing. But it's not unheard of," said Matthews, adding that Heist did not strike him as a good candidate for that. She told Schofield she never had access to a computer to check if she was being sought, but she assumed people were looking for her.
"I would not have expected to see her turn up alive," Matthews said.
Brenda Heist's true identity came to light after she turned herself in to Monroe County sheriff's deputies in Key Largo, Fla., on Friday and informed them she was a missing person.
She told them she was on probation and had recently been arrested under a name different from her real name, but the nature of those charges was not clear in a Monroe County sheriff's office report released late Wednesday.
Schofield said she was expected to be released from police custody in Florida and was likely to spend some time with a brother there before moving in with her mother in Texas.
When Schofield called recently to meet with Lee Heist and the couple's daughter, they assumed he would be notifying them that her remains were found, the detective said.
Schofield said police in Florida were trying to sort out a warrant-related issue before releasing Brenda Heist. Details about any charges, and whether she was being held on an active warrant, were not available from authorities in Florida or Pennsylvania.
The Monroe County sheriff's office said Heist was in "protective custody," although not with the office. The sheriff's office did not immediately respond to a request by The Associated Press to provide a way to contact her.
Police in Lititz said the missing persons case eventually involved dozens of detectives, and although the trail had grown cold, the case had never been forgotten, with Heist's picture tacked to a wall at police headquarters.
Lee Heist said he and the children also remembered, and observed anniversaries. Her valuables were returned to her mother years ago, he said. As for the life insurance policy that paid off on his ex-wife, he said he's unsure what will happen now.