John Ferak

USA TODAY NETWORK-Wisconsin

CAMPBELLSPORT - Nearly half of Sharon Szabo’s life has been consumed with heartbreak and grief. She’s in her early 70s and constantly relives and reels from the day her “little angel” vanished.

Saturday, May 14, 1983.

Her 5-year-old son, Bobby Joe Fritz, a blonde-haired boy who liked to pedal his Big Wheel in front of his mother's house and curl up in her arms, went outside to play with his older siblings. They joined a group of friends in a large open field bordering the St. Joseph convent and the mill pond on the outskirts of Campbellsport.

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When the Fritz kids were called home for supper, Bobby Joe was absent from the table. Everyone went scurrying back outside to look for him. He was nowhere to be found. A neighbor called police at about 5:15 p.m., and Campbellsport was rampant with chaos and confusion as the night wore on without any sign of the missing child.

Bobby Joe hasn’t been seen or heard from since that spring afternoon.

His disappearance ranks as one of Wisconsin’s most enduring missing-child cases and is believed to involve an exceedingly rare crime. Only about 1 percent of children who vanish were abducted by strangers.

USA TODAY NETWORK-Wisconsin spent weeks poring through hundreds of old police reports, criminal court records and newspaper archives to determine why the case is unsolved after 34 years. It was during this analysis that fresh hope emerged, the possibility that advances in DNA technology will unearth the truth about what happened to Bobby Joe Fritz.

If modern science can crack the case, it would come after numerous land and water searches, accusations that police lost or destroyed evidence, and the treatment of Bobby Joe's own parents as suspects. Solving the mystery would help bring closure to a weary family, to investigators who spent years on the case, and to the residents of Campbellsport who struggled with the idea that a predator had infiltrated their town.

'I think he's dead'

While some initially suspected Bobby Joe drowned in the nearby mill pond, the prevailing theory is that he was abducted and killed. Investigators came to believe that the boy was buried in neighboring Sheboygan County near Waldo.

The Fritz family remains shattered three-plus decades after he went missing. He was just a few months shy of his sixth birthday.

“I was hoping they would have found Bobby Joe before I died,” his mother told USA TODAY NETWORK-Wisconsin. These days, Szabo lives in Stephenson in Michigan's Upper Peninsula.

“I’ve given up all hope on everything," she said. "It's hard for me to admit it, but I think he's dead. It's been 34 years. There is no sign of him. I can only hope so much."

Lora Engel was 11 when her brother vanished.

"As a child, I just remember being very sad a lot," she said. "Everything about that day has been replayed many times by myself and my brothers and sisters. I just always had hope that he was still alive.

"Bobby Joe was just everyone's favorite. Everyone adored him, and he liked to play outside."

A difficult investigation

Retired Fond du Lac County Sheriff's Lt. Ed Sheppard said Bobby Joe's case was incredibly taxing.

"It was a lot of frustration," Sheppard said in a recent interview. "Most of our detectives were pretty successful in most of their cases they did, but this was one I could not force the investigation in one direction or the other. You had to leave all options on the table."

About five years ago, the mill pond in Campbellsport was drained as part of a public works project to reconfigure the Milwaukee River. No sign of Bobby Joe's body, or his clothing, turned up.

"Most of the investigators tended to feel he was probably abducted by a sexual predator or somebody with a parenting instinct," Sheppard said.

One year after Bobby Joe vanished, authorities in Sheboygan County identified a convicted child sex offender named Michael Scott Menzer as a strong suspect in his disappearance. However, Bobby Joe's investigation would not make any substantial inroads at the time. In October 1990, investigators tore up Menzer’s property in the tiny village of Waldo, current population 500, in an effort to find Bobby Joe's buried body or clothes.

Remnants of decayed children's clothes and four small bones were found within Menzer's property, according to search warrant records. The documents reflect that Lynn Rusch, an archaeologist at the Wisconsin Historical Society, "could not tell if it was animal or human, but stated that due to the fact that the hip socket had not fused itself to the long bone, it appeared to be that of a juvenile."

However, DNA technology was in its infancy, so the evidence was not subjected to advanced scientific testing. Time elapsed. The clues remained inside an evidence storage unit. Menzer was never charged in connection with Bobby Joe’s kidnapping, but was given a 40-year federal prison sentence in 1993. A jury convicted him of burning down his Waldo Mill property in 1990, killing his stepsons, ages 8 and 7. In 2008, Menzer died of cancer while in custody. He was 59.

The lack of answers makes Bobby Joe's disappearance that much more troubling to bear, said Tony Fritz, an older brother who lives in Illinois.

"I think (Menzer) took more to the grave than what they know about," Tony Fritz said.

No easy answers

Now 47, Tony Fritz briefly moved to Campbellsport around 2000 as a personal quest to find his missing brother.

"I hung out fliers. I searched ponds, knocked on doors, just general canvassing," he said. "I still want him found, whether he's alive or dead. I won't give up on him, ever. As far as the person who did this, he's done ruined everybody's lives."

Szabo said she is not sure whether Menzer was involved in Bobby Joe’s death.

"They asked him about Bobby Joe and some other kids and he never cooperated," she said. "They never had any proof he was in Campbellsport."

Sheppard, who retired from the Fond du Lac County Sheriff's Department in 2003, said he was glad to have obtained a DNA sample from Bobby Joe's mother before he left the job in the hope that modern technology could lead to a break in the case.

Unwelcome and under suspicion

Another factor that played into the investigation, Sheppard said, was that Bobby Joe's parents had "gone through a bitter divorce."

Investigators explored the possibility that the boy was picked up and taken to his father's home six hours away in downstate Illinois. A week after Bobby Joe vanished, authorities in Fond du Lac County mobilized a massive volunteer search to walk a five-mile area near Campbellsport. That same day, the boy's father was remarrying in Illinois, Sheppard recalled.

A mother of seven in her late 30s, Sharon (Fritz) Szabo moved to Wisconsin in 1982 after her marriage ended. She settled in Campbellsport, having family in nearby Kewaskum. Five children lived with their mother while Tony Fritz and another brother stayed in Illinois with their father.

During the investigation, Szabo was put under the microscope, enduring a barrage of confrontational questions from FBI agents.

"A couple of the detectives from the FBI came to my house and hollered, 'What did you do with Bobby Joe?' They thought I killed him and got rid of his body," she recalled. "I told them to get out and not to come back."

People around town also speculated that Bobby Joe's mother gave away her son or sold him because the family had little money. At the time, she was collecting public assistance to make ends meet.

Eventually, both of the boy's parents were cleared as suspects.

As time passed, life around Campbellsport became too unbearable for his mother. The Fritz case dominated the newspaper headlines for months, infuriating some people around the Fond du Lac County village who felt the constant press was giving their otherwise peaceful community a black eye and unflattering attention.

“I was very upset, and my mind wasn’t working right. We got to the point where we didn’t want to leave the house," Szabo recently told USA TODAY NETWORK-Wisconsin.

About six months after Bobby Joe went missing, Szabo packed up her family and left Campbellsport. She moved 50 miles away, renting a duplex in Milwaukee.

'Case file got shredded'

The Fritz family hasn’t received any updates on the case in years. Lora Engel, Bobby Joe’s sister, submitted a letter to the Sheriff's Department last August, seeking access to her brother's case files. The department rejected the family's records request, claiming the case remains active.

Incidentally, last May, sworn testimony arose during an unrelated Fond du Lac County murder case, suggesting the Sheriff's Department had inadvertently lost or destroyed its original investigative files pertaining to the Fritz case. The testimony came from Daniel Kaminsky, the Fond du Lac County district attorney from 2009 through 2012, who is now in private practice.

"The case file got shredded," Kaminsky testified. "I'm certain that I have heard that from former Detective (Gerry) Kane, Detective (Eric) Muellenbach. I believe I may have heard it from ... Detective Cameron McGee. I know that I have heard it from several officers on the city (of Fond du Lac) side who I regularly talk with.

"I did not investigative that myself," Kaminsky told the courtroom. "In other words, people told me this and that's as far as the information went."

McGee, Fond du Lac County's lieutenant detective who has been in charge of the Fritz case since 2015, did not return calls seeking comment for this story.

That Bobby Joe's case has not been a high priority for Fond du Lac County for many years only adds to the family's pain.

"I would like to know what happened, but I don't think I will. Look at how many cases are never solved," Szabo said. "It’s been so damn long. Unless someone came forward with new evidence, what progress could they make?"

Rediscovered evidence

Since USA TODAY NETWORK-Wisconsin began investigating Bobby Joe's case, the Sheboygan County Sheriff's Department has rediscovered the unidentified bones on an additional evidence storage shelf. Investigator Corey Norlander plans to submit the bones to the University of North Texas Center for Human Identification laboratory to hopefully determine if they're human and belong to Bobby Joe.

In addition, a Pennsylvania police laboratory with revolutionary DNA testing equipment has offered to re-test the decayed children's clothes that were dug up around Menzer's property in Waldo 27 years ago. Even though Bobby Joe disappeared from Campbellsport, Sheboygan County remains involved because Menzer might have buried the boy's body inside their jurisdiction.

"If there's a possibility that some DNA evidence could be extracted based on new technology and techniques, we would have an interest in that," Sheboygan sheriff's Inspector Jim Risseeuw said. "Whether it could bring total closure or at least some closure to the family of this boy, it would be well worth the time and effort."

John Ferak of USA TODAY NETWORK-Wisconsin: 920-993-7115 or jferak@gannett.com; on Twitter @johnferak