How I used both Mitochondrial and Autosomal DNA to prove a great grandmother’s maternal line. When no paper trail gives answers, sometimes we can turn to DNA to provide the proof of the relationship and then introduce new documentary evidence to draw a valid conclusion. In this case, my father’s maternal grandmother’s parents were a complete mystery but I was able to conclude who her mother and grandparents were using DNA and documented evidence. Since her mother was not married and no evidence at this time, her father remains a mystery. For now.