Overview

Last Seen: May 14, 1983
Location: Campbellsport, Fond du Lac County, Wisconsin
Age: 5 years old
Date of Birth: August 5, 1977
Classification: Non-family abduction
NamUs: MP6085
NCMEC: 601377
NCIC: M101296801
Doe Network: 101DMWI

Bobby Joe was last seen outside in Campbellsport during the afternoon of May 14, 1983. Official Wisconsin and NCMEC records place the last-seen window between approximately 2:30 p.m. and 4:30 p.m. He was described as having blond hair and blue eyes, standing about 4 feet tall and weighing approximately 50 pounds. He had a distinctive red or strawberry-colored birthmark on his outer left thigh above the knee and had difficulty pronouncing the letters T, K and R.

The Wisconsin Department of Justice currently classifies the disappearance as a non-family abduction.

Detailed Case Breakdown

Robert Joseph “Bobby Joe” Fritz: The 1983 Campbellsport, Wisconsin Disappearance and 2026 Investigation

Robert Joseph Fritz, commonly known as Bobby Joe Fritz, was only five years old when he disappeared from Campbellsport, Wisconsin, on May 14, 1983. More than four decades later, his case remains open—and in July 2026, investigators made one of the most significant moves in the investigation in years, searching and excavating the basement of the home where Bobby Joe lived when he vanished.

Brief Case Summary

Last Seen: May 14, 1983
Location: Campbellsport, Fond du Lac County, Wisconsin
Age: 5 years old
Date of Birth: August 5, 1977
Classification: Non-family abduction
NamUs: MP6085
NCMEC: 601377
NCIC: M101296801
Doe Network: 101DMWI

Bobby Joe was last seen outside in Campbellsport during the afternoon of May 14, 1983. Official Wisconsin and NCMEC records place the last-seen window between approximately 2:30 p.m. and 4:30 p.m. He was described as having blond hair and blue eyes, standing about 4 feet tall and weighing approximately 50 pounds. He had a distinctive red or strawberry-colored birthmark on his outer left thigh above the knee and had difficulty pronouncing the letters T, K and R.

The Wisconsin Department of Justice currently classifies the disappearance as a non-family abduction.

The Disappearance of Bobby Joe Fritz

On Saturday, May 14, 1983, Bobby Joe was outside with other children in his Campbellsport neighborhood. The Wisconsin Department of Justice states that he was last seen playing outside with his siblings sometime between 2:30 and 4:30 that afternoon.

More detailed accounts report that Bobby Joe and other children had been playing in an empty lot roughly half a block from his home, near the Mill Pond and Milwaukee River. According to those accounts, Bobby Joe told his sister that he was hungry and intended to go home. He never arrived. A toy gun he had been playing with was reportedly later recovered.

Bobby Joe was wearing a red, blue and gray shirt, dark blue pants and brown cowboy boots when he disappeared.

The Search for Bobby Joe

An extensive search began after Bobby Joe disappeared. Searchers examined the surrounding community and waterways, including the Milwaukee River and Mill Pond. The sheriff’s department dive team searched the river and the Mill Pond north of the dam, but no trace of the five-year-old was found.

The absence of evidence indicating that Bobby Joe had fallen into the nearby water eventually contributed to authorities’ belief that he was more likely abducted. The Wisconsin Clearinghouse continues to officially classify the case as a non-family abduction.

A Suspect Investigated in the Case

Over the years, investigators examined possible suspects and leads. One of the individuals publicly associated with the investigation was convicted sex offender Michael Scott Menzer, who lived at the Waldo Mill, less than 20 miles from Campbellsport. According to The Charley Project, Menzer was identified as a suspect approximately a year after Bobby Joe disappeared.

Authorities searched Menzer’s property and reportedly discovered child sexual-abuse material, newspaper clippings concerning Bobby Joe’s disappearance, deteriorated children’s clothing and small bones. The bones could not initially be established as human. The existence of these discoveries generated considerable attention, but no publicly documented evidence established that Menzer was responsible for Bobby Joe’s disappearance.

Menzer was later convicted in an unrelated case involving the 1990 fire at the Waldo Mill that killed his two young stepsons. Bobby Joe’s disappearance, however, remained unresolved.

The Case Remained Active for Decades

Bobby Joe’s information remained in national and state missing-person databases. The National Center for Missing & Exploited Children currently lists him as missing and displays an age-progression image depicting how he might have appeared at age 42.

The Doe Network also continued maintaining his case. Its records show Robert Joseph Fritz as case 101DMWI, and the organization recorded another update to his case information on August 12, 2026, following the major investigative activity that summer.

Major Break in the Investigation: July 2026

The case received renewed attention in 2026 after Fond du Lac County investigators revisited the original evidence and case files.

According to information released by the sheriff’s office, detectives had spent the previous year identifying and interviewing several people who could have connections to the investigation. Significantly, authorities said some of those individuals had apparently never previously been interviewed. Investigators combined information from those interviews with a fresh review of the original case file. Authorities said the resulting information established sufficient probable cause to obtain a search warrant.

On July 16, 2026, Fond du Lac County Sheriff’s Office detectives executed that search warrant at the Campbellsport residence where Bobby Joe had lived in 1983.

Investigators reported locating potential evidence during the initial search. That discovery led authorities to undertake a much larger forensic excavation of the home’s basement.

Investigators Excavate Bobby Joe’s Former Home

The excavation became a substantial forensic operation involving Fond du Lac County Sheriff’s Office detectives, Wisconsin Department of Justice Division of Criminal Investigation agents, crime-scene personnel, crime-lab personnel and a forensic anthropologist.

Investigators removed approximately 500 five-gallon buckets of soil from the basement by hand—about 30,000 pounds of dirt. The soil was then sifted and searched by hand for evidence. The excavation itself was conducted with hand tools.

The search was completed on July 21, 2026, and the residence was returned to its current owner, whom authorities emphasized has no connection to the Fritz family or Bobby Joe’s disappearance.

No Remains Found, but New Potential Evidence Recovered

Investigators did not locate Bobby Joe’s remains during the excavation.

They did, however, recover additional items described as having potential evidentiary value. Authorities said the recovered material would be sent to specialized laboratories for detailed examination. The testing process could require several months and, in some circumstances, more than a year.

The exact nature of the evidence has not been publicly disclosed. Investigators have said that additional information will be released only when doing so will not compromise the active investigation.

Latest Investigation Information

As of the latest publicly available developments located for this article, Robert Joseph “Bobby Joe” Fritz remains missing and the Fond du Lac County Sheriff’s Office investigation remains active.

The July 2026 search did not recover his remains, but investigators collected potential evidence for specialized laboratory analysis. Authorities have expressed hope that those items could produce new leads or provide additional insight into what happened in 1983.

The renewed investigation was not simply a routine search of the old residence. Authorities said it resulted from a fresh examination of the original case, modern investigative resources and interviews conducted during the preceding year—including interviews with people who had apparently never been questioned before.

A further indication that the case remains active came on August 12, 2026, when The Doe Network recorded that its Robert Joseph Fritz case file had been updated.

More than 43 years after Bobby Joe disappeared, investigators are therefore still pursuing the question at the center of the case: What happened to five-year-old Robert Joseph Fritz after he was last seen in Campbellsport on May 14, 1983?

Anyone with information—even information that may have seemed insignificant decades ago—is encouraged to contact investigators.