An American student who disappeared in November most likely fell drunkenly into the city's Main River, Frankfurt police said Friday.
Devon Hollahan, 22, who had been teaching English in Prague since July, was traveling back to a hostel after a concert with a friend, who stopped to ask for directions at about 3 a.m. on Nov. 21. When the friend turned back around, Hollahan was gone.
Police said in a statement that dogs traced Holllahan's trail to the banks of the river, and that authorities found a shoe believed to be his in the waters.
Police said they "have to assume that Devon Hollahan, in a helpless state in connection with alcohol, fell into the Main."
Jeff Hollahan, Devon's father, traveled to Frankfurt the week after Devon's disappearance and canvassed the city searching for him. The Scottsdale, Arizona man posted fliers with pictures and contact information all over the city, hoping to get a lead.
He returned home on Wednesday after hearing the news and said the family is "still coming to grips with it" but told The Associated Press by phone that he is still holding out hope.
"The search hasn't been called off," he said. "The search is ongoing until a body is found."
After Hollahan disappeared, the friend headed to the hostel, where he spent the night and then went back to Prague alone the next day.
According to police, witnesses saw a man who was "without a doubt" Hollahan lying on the sidewalk at about 4 a.m. and called for an ambulance. But after the witnesses told Hollahan in English that they had called an ambulance, he got up and ran away. His backpack was found shortly thereafter by a security guard.
Police said there were no clues pointing to either a suicide or a crime.
The police said that during the course of the search, they had interviewed Hollahan's family, but that did not lead to any new clues. They also searched parks, underground tunnels and other areas near where Hollahan disappeared.
The U.S. Consulate in Frankfurt was also involved in the search.