But away from the workplace, back in the world of the criminally violent psychopath, Hare's checklist has become broadly known, so broadly known, in fact, that it is now a constant source of concern for him. "People are misusing it, and they're misusing it in really strange ways," Hare says. "There are lots of clinicians who don't even have a manual. All they've seen is an article with the twenty items -- promiscuity, impulsiveness, and so forth -- listed."
In court, assessments of the same person done by defence and prosecution "experts" have varied by as much as twenty points. Such drastic differences are almost certainly the result of bias or incompetence, since research on the PCL-R itself has shown it has high "inter-rater reliability" (consistent results when a subject is assessed by more than one qualified assessor). In one court case, it was used to label a thirteen-year-old a psychopath, even though the PCL-R test is only meant to be used to rate adults with criminal histories. The test should be administered only by mental-health professionals (like all such psychological instruments, it is only for sale to those with credentials), but a social worker once used the PCL-R in testimony in a death-penalty case -- not because she was qualified but because she thought it was "interesting."
It shouldn't be used in death-penalty cases at all, Hare says, but U.S. Federal District Courts have ruled it admissible because it meets scientific standards.