Previous studies documented that crime is heavily concentrated in families. However, many studies relied on relatively small samples, often males and information on criminal involvement was self-reported. The present study investigates: (1) the prevalence of arrests in three generations; (2) the concentration of offenders and arrests within families; (3) the relationships between arrests among the relatives; (4) the relationship between arrests and family violence. A complete cohort of the families in which a child was born in a Dutch city was selected, and the arrests of all known family members (siblings, parents and grandparents) were investigated. Results showed that 7.2 % of the mothers and 18 % of the fathers had been arrested. The likelihood of parental arrests was related to the likelihood of grandparental arrests. There was clear evidence for assortative mating: when the mother was arrested, the likelihood that the father was arrested was increased with a factor five. Maternal arrests were also related to arrests of her parents-in-law. Arrests are heavily concentrated within families, 7.8 % of the families account for 52.3 % of the suspects. Arrests in family members constitute a major risk factor for poor developmental outcomes, such as criminal behavior. At the time of birth, it is possible to use information on arrests to select children who are at relatively high risk for the target of prevention efforts.Implications for prevention policies are discussed.