OTTAWA—An investigation into the conduct of Canada’s top military officer Admiral Art McDonald has ended with police saying there is not enough evidence to lay charges. Provost Marshal Brig.-Gen. Simon Trudeau announced the end of the investigation on Friday evening, nearly six months after the Canadian Forces National Investigation first revealed that it was investigating the chief of defence staff. “The CFNIS was able to both identify and interview a large number of potential witnesses,” Trudeau said. “The evidence gathered from these witnesses was considered in the ultimate determination that the evidence did not support the laying of any charges.” The decision paves the way for McDonald to return to his position as commander of the Canadian Armed Forces after he voluntarily stepped down in February due to revelations about the military police investigation. But it is also likely to spark fresh questions about the military’s ability to properly address …