 The criterion for falsehood was simply a denial of a polygraph test of the accuser.A 1998 report by the National Institute of Justice found that DNA evidence excluded the primary suspect in 26% of rape cases and concluded that this "strongly suggests that postarrest and postconviction DNA exonerations are tied to some strong, underlying systemic problems that generate erroneous accusations and convictions".However, this study also noted that analyzed samples involved a specific subset of rape cases (e.g.