I'm trying to find information on a George Mahoney (my 2nd great grandfather) who was engaged by the Northwest Mounted Police in Winnigpeg, Manitoba in approximately 1875 and subsequently drowned during a river crossing while on duty in June 1877. He married Emma Ballendine in approximately 1874/75 in Winnipeg or that general area. Due to the lack of information (due to a fire involving the early NWMP records), I need help with a date & place of birth as well as names of parents and/or siblings.

Any help would be appreciated!