The sample represented all the 8- and 9-year-old boys in one grade at six State primary schools. They were followed for 12 years through checks of records in the Criminal Record Office of Scotland Yard. A total of 27.9 percent had a criminal record. If the father had a record, the chances both of having a criminal record and of becoming a recidivist were significantly increased. In addition, over half the boys with criminal mothers had records, in comparision with only 22.8 percent of the boys with noncriminal mothers. Having a brother with a criminal record was also associated with a higher rate of criminality. These figures may reflect police activity, rather than family deviance. Once any family member acquires a police record, the risks of detection and prosecution may increase for all family members. It is also possible that the communication of criminality from fathers to sons takes place indirectly, perhaps by means of transmission of antiauthority attitudes. Further data analysis did not indicate that poor parental supervision or low social status were crucial factors. The selective prosecution of persons from families in which someone has a criminal record appears to be an important factor, however. Seven data tables and six references are listed.