They found that rates of victimization, as measured by NCS data, are systematically related to residual gain scores in UCR data on crimes known to the police and that rates of crimes known to the police, as measured by UCR data, are systematically related to residual gain scores in NCS victimization rates. They cautioned, however, that their results may not be generalizable to other crime types. The critique of their conclusions questions how reliably Blumstein, Cohen, and Rosenfeld measured the crime phenomenon. To state that the two data series tell the same story ignores past research on differences between victimization and official statistics and concentrates only on the results of residual gain scores. The critique does not argue that UCR and NCS crime rates should be completely unrelated to each other. Both should be affected by true rates of illegal behavior. There are sufficient differences in the construction of the two measures, however, to suggest that even if what they measure includes the true rate of crime for both, each also measures conceptual variables not measured by the other. Further, the two data series do not measure the true rate of crime equally well. Which is the better measure varies by crime type and the purpose for which crime is being measured. 17 references