There are several possible reasons for this failure: (1) the putative age/crime relationship may be much weaker than previously thought; (2) the wrong age structure may have been used; (3) other factors may have intervened and overshadowed the age/crime relationship; or (4) the Uniform Crime Report data may be misleading. Research on the age/crime relationship has used two separate approaches that involved different data and different statistical techniques, and the approaches produced opposing results. Studies using age-at-arrest data suggest a strong age/crime relationship. Studies regressing crime rates on the size of supposed high-crime age groups usually suggest that there is no relationship. It is fair to conclude that at least one of these bodies of research is faulty, but there is not sufficient information to determine which one. The absence of a comprehensive theory and the arrest data patterns suggest that relationships probably differ greatly between crime types. 10 tables, 8 footnotes, and 123 references (Author abstract modified)