Party officials had responsibilities for supervising the work of justice agencies and disciplining wayward members of the party. Consequently, the essay first investigates to what extent the execution of these functions encouraged interventions into the prosecution of particular cases. This discussion concludes that party officials who supervised legal agencies rarely involved themselves in cases. Secret party rules, however, gave party secretaries the authority to screen prosecutions against members of the party until Krushchev's time. The practice survived informally from 1964 through 1984 and was ignored by Soviet leaders. The essay examines the dynamics of intervention, especially resistance to party advice and the resolution of conflicts. It suggests that rationales for intervention fell into two categories: protecting executives who had committed corporate crimes and protecting persons whose prosecution seemed to discredit the party or the state. Some party secretaries also used their leverage over legal officials to serve wholly personal goals. The author discusses consequences of intervention, factors contributing to leaders' tolerance in the post-Krushchev era, and reform strategies. Data on informants and 71 footnotes.