Defense lawyers have long questioned the reliability of some forensic science methods, but over the past decade, the debate has intensified. Two highly critical reports found that with the exception of DNA, many methods have not been tested rigorously enough to be considered scientifically valid. A look at various forensic methods coming under fire and what the 2016 report from the President's Council of Advisors on Science and Technology had to say about them: ___ BITE MARKS Involves examining marks left on a victim or object, then comparing those with dental impressions taken from a suspect.