Joseph Zak, 34, disappeared from a group home on a 160-acre rural farm in Brookston, Minnesota, on December 7, 2015. He was last seen at 7:15 a.m., behaving normally as he prepared for the day, then went into his room to shower and did not return. Staff later found that he had left the home through a bathroom window.

Joseph was autistic and took prescribed medications for multiple mental and physical health conditions, which were left behind. Because of his disabilities he was considered highly vulnerable. He had a history of wandering and had once been found in a river suffering psychological distress. Searches turned up only a brief cellphone signal near Esko, Minnesota, and a cadaver dog detected a scent near the St. Louis River; investigators fear he may have drowned but his whereabouts remain unknown and the case is unsolved.

Anyone who knew Joseph, saw him in December 2015, or has information about the area between Brookston and Esko is asked to come forward with tips.