Mio, MI (WOWO) Forty years after two metro Detroit men disappeared during a deer hunting trip, the case remains one of Michigan’s most unsettling criminal mysteries.

David Tyll and Brian Ognjan, both 27, left for Oscoda County in November 1985 and were last seen at a bar west of Mio. When they failed to return to work, their families reported them missing, setting off an extraordinary years-long investigation that stretched across northern Michigan.

Search teams scoured forests, lakes and trails. Flyers were posted statewide, and tips poured in from across the country. Despite the massive effort, authorities found no trace of the men, their truck, or their equipment according to Bridge Michigan.

Over the years, rumors centered on two brothers from the area, Raymond and Donald “Coco” Duvall, who were known locally for violent behavior. Investigators heard repeated secondhand claims that the brothers had boasted about killing the hunters, but there was no physical evidence to support charges.

The case changed after Michigan State Police Detective Robert “Bronco” Lesneski re-opened old leads in the late 1990s. He eventually connected with a woman who had long been afraid to come forward. Her testimony placed the hunters at the bar on the night of their disappearance and described a violent attack involving the brothers.

In 2003, prosecutors charged and convicted the Duvall brothers with murder. The trial relied heavily on eyewitness testimony and circumstantial evidence; the victims’ bodies were never located.

Retired investigators believe others may have been involved, and they suspect the men’s remains were destroyed shortly after the killings. The motive for the attack remains unclear.

Though the convictions brought some relief to the families, the absence of the victims’ remains continues to cast a shadow over the case. The story is often retold each November as hunters return to the region, keeping alive one of Michigan’s most haunting unsolved mysteries—partially solved, but never fully understood.