The narrative about Sergeant Bergdahl over the past few days has undergone a rapid evolution based on accounts by current and former soldiers, which have grown increasingly dark. They have gone from saying he should not be treated as a hero because he was a deserter and blaming the subsequent search for him for every American combat death in the province over a three-month period, to alleging that there is evidence that he was trying to meet up with the Taliban.

Amid the controversy, an event in his hometown, Hailey, Idaho, to celebrate his return has been canceled. But the accounts of the investigative report, which was described as meticulous and thorough, suggest that even basic facts necessary to understand how he came to disappear have yet to be definitively established.

The people briefed on the “15-6 report,” named for the army regulation covering such investigations, described it on the condition of anonymity because it remains classified. The report was written by an investigating officer in July and August of 2009 after extensive interviews with members of Sergeant Bergdahl’s unit, including his squad leader, platoon leader, and company and battalion commanders.

It is said to confirm certain other details relayed in recent accounts, including that Sergeant Bergdahl shipped his computer and a journal home before he disappeared. It also confirms that he left behind his body armor and weapon — an unwieldy SAW machine gun — taking with him water, knives and a compass.

The report speculates that he most likely left in darkness after the moon had set, following one of two possible routes through the concertina wire.