Recent panel studies of deterrence have reported little evidence that perceptions of legal sanctions promote deterrence. Yet those studies have consistently found that extralegal sanctions "inhibit" criminal involvement. Conclusions drawn from this line of research remain speculative, however, because they are guided by an unnecessarily narrow conception of deterrence, the distinction between legal and extralegal sanctions is unclear, and the analyses conducted gloss over some potentially relevant measurement distinctions. To address these issues, data from one wave of an ongoing national panel study of assaults between adult partners were used to assess the perceived costs associated with the perpetration of assaultive action and the perceived costs associated with being sanctioned (i.e., arrested) for such action. Based on results of the study, it was proposed that the costs seen as flowing from arrest, identified as attachment loss, social stigma, and self-stigma, should be considered part of the deterrence process. Judgments about how engaging in some illegal act might create costs in these three areas for perpetrators are seen as extralegal sources of control, not as part of deterrence. Future research might attempt to assess the controlling power of costs associated with actual and potential arrest for a variety of illegal acts. (Fourteen endnotes are included.) (Author/NB)