Overview

Date last seen: May 12, 2019
Location: Oshkosh, Winnebago County, Wisconsin
Age when missing: 30
Date of birth: December 10, 1988
Height: Approximately 5 feet 9 inches
Weight: Approximately 160 pounds
Hair: Brown
Eyes: Brown
Race: White
NamUs case number: MP62404
Oshkosh Police case number: 19-013916

Circumstances at a Glance

Andrew Hildebrand was interviewed by Oshkosh Police detectives on May 12, 2019, concerning a sexual-assault investigation involving an incident in the 800 block of Cherry Street in Oshkosh.

Later that night, Hildebrand was reported missing and police initiated a welfare check.

His vehicle was located two days later, on May 14, near the Auburn Lake boat launch in Fond du Lac County. Authorities searched the area but did not locate him.

Police reported that Hildebrand was familiar with the Kettle Moraine State Forest area and was believed at the time to possibly have a .22-caliber rifle. Police also stated that he had made no threats to harm members of the public.

Detailed Case Breakdown

Andrew M. Hildebrand Missing Person Case: Oshkosh Man Missing Since May 2019

Andrew M. Hildebrand was 30 years old when he disappeared from Oshkosh, Wisconsin, on May 12, 2019. His disappearance occurred on the same day Oshkosh Police detectives interviewed him in connection with a sexual-assault investigation. Two days later, his vehicle was discovered near the Auburn Lake boat launch in Fond du Lac County, triggering an extensive search of the surrounding area.

Last Seen: May 12, 2019 — Oshkosh, Wisconsin

Date last seen: May 12, 2019
Location: Oshkosh, Winnebago County, Wisconsin
Age when missing: 30
Date of birth: December 10, 1988
Height: Approximately 5 feet 9 inches
Weight: Approximately 160 pounds
Hair: Brown
Eyes: Brown
Race: White
NamUs case number: MP62404
Oshkosh Police case number: 19-013916

Circumstances at a Glance

Andrew Hildebrand was interviewed by Oshkosh Police detectives on May 12, 2019, concerning a sexual-assault investigation involving an incident in the 800 block of Cherry Street in Oshkosh.

Later that night, Hildebrand was reported missing and police initiated a welfare check.

His vehicle was located two days later, on May 14, near the Auburn Lake boat launch in Fond du Lac County. Authorities searched the area but did not locate him.

Police reported that Hildebrand was familiar with the Kettle Moraine State Forest area and was believed at the time to possibly have a .22-caliber rifle. Police also stated that he had made no threats to harm members of the public.

The Disappearance of Andrew Hildebrand

On May 12, 2019, detectives with the Oshkosh Police Department interviewed Andrew M. Hildebrand as part of an investigation into an alleged sexual assault in the 800 block of Cherry Street in Oshkosh.

According to the police department’s subsequent public statement, Hildebrand was reported missing later that night. Authorities then began a welfare check and attempted to determine where he had gone.

The investigation shifted approximately 30 miles south of Oshkosh after Hildebrand’s vehicle was discovered on May 14, 2019, near the boat launch at Auburn Lake in Fond du Lac County.

The location was significant because Hildebrand was reportedly familiar with the Kettle Moraine State Forest region. The discovery of the vehicle resulted in an extensive search of the area, but investigators found no sign of him.

Extensive Search Near Auburn Lake

The search for Hildebrand involved considerably more than a basic ground search.

According to Wisconsin Missing Persons Advocacy, citing information from Fond du Lac County Sheriff’s Capt. William Tadych, search efforts included police dogs, drones, an airplane, a Wisconsin Department of Natural Resources boat, submersible robots and sonar equipment. Despite those resources, Hildebrand was not located.

The Oshkosh Police Department’s May 21, 2019, release similarly reported that the Fond du Lac County Sheriff’s Department had conducted an extensive ground and aerial search after Hildebrand’s vehicle was located.

Criminal Charges and Arrest Warrant

As authorities searched for Hildebrand, a criminal case was also proceeding.

WBAY reported that a criminal complaint filed May 20, 2019, charged Hildebrand with two counts of first-degree child sexual assault, as well as invasion of privacy and attempted invasion of privacy. The following day, Oshkosh Police publicly announced that authorities were seeking Hildebrand and that an arrest warrant had been issued.

These are allegations. Hildebrand has not been convicted of the alleged offenses discussed here, and the Oshkosh Police Department specifically noted in its release that the charge was an accusation and that he was presumed innocent unless proven guilty.

At the time of the search, police also cautioned that Hildebrand was believed to possibly have a .22-caliber rifle. Authorities said, however, that he had not made threats to harm the public.

What Happened After the Search?

No publicly documented discovery of Hildebrand resulted from the searches described by authorities.

Wisconsin Missing Persons Advocacy reported in its case summary, updated in January 2022, that no one had seen or heard from Hildebrand since his disappearance.

The case has remained publicly listed well beyond the initial 2019 investigation. Hildebrand continued to appear in community missing-person awareness discussions in 2024 and 2025, including posts drawing attention to unresolved Winnebago County cases and the possibility that evidence could remain in the Kettle Moraine region. Those posts represent community discussion rather than official investigative findings.

Latest Publicly Available Case Status

As of the most recent records located for this article, Andrew Hildebrand remains officially listed as a missing adult by the Wisconsin Department of Justice Clearinghouse for Missing & Exploited Children & Adults. The state listing identifies his missing date as May 12, 2019, his missing location as Oshkosh and his last known location as Oshkosh, Wisconsin.

The current state listing directs anyone with information to the Oshkosh Police Department at 920-236-5700. The Wisconsin Clearinghouse can also receive information at 1-800-843-4673.

A search for more recent publicly accessible official investigative announcements did not locate a newer substantive law-enforcement update explaining what happened to Hildebrand. The continued Wisconsin DOJ listing indicates that the missing-person case has not been publicly resolved.

There has been no publicly confirmed finding in the sources reviewed that Hildebrand is deceased, and his case should therefore not be characterized as a homicide unless authorities release evidence establishing that conclusion.

The Questions That Remain

More than seven years after Andrew Hildebrand disappeared, the central question remains unanswered: what happened after he left Oshkosh on May 12, 2019?

His vehicle’s discovery at the Auburn Lake boat launch provided investigators with a major clue, and authorities devoted ground, aerial, water and specialized search resources to the surrounding area. Those efforts nevertheless failed to establish his whereabouts.

The circumstances surrounding Hildebrand’s disappearance are unusual because his missing-person investigation unfolded at the same time authorities were pursuing serious criminal allegations against him. Those two aspects of the case are documented, but neither establishes what ultimately happened after his disappearance.

For now, Wisconsin authorities continue to list Andrew M. Hildebrand as missing, and investigators are still seeking information that could determine where he went after May 12, 2019.