This research compared independent ratings of criminal psychopathy (Ha
re's Psychopathy Checklist, Hare, 1991) from National Parole Board cas
e files alone with ratings based upon file information plus a semi-str
uctured interview. Notwithstanding high interrater reliability using N
ational Parole Board (NPB) case files alone (n = 35), Psychopathy Chec
klist (PCL-R) scores had to be prorated because 30% of the items could
not be scored. Comparisons between file only and independent file plu
s interview ratings of criminal psychopathy for a larger sample (N = 1
20) resulted in relatively low interrater reliability. Interrater agre
ement for ratings of psychopathy with and without an interview was sta
tistically significant (p < .006), yet 40% of the cases received diffe
rent diagnoses when the different procedures were used. Contrary to ea
rlier findings (Wong, 1988), file only PCL-R ratings were not routinel
y an underestimate of file plus interview PCL-R ratings.