The systemic model posits that informal control reduces crime and that social networks reduce crime indirectly by stimulating informal control. The systemic literature consistently supports the informal control-crime relationship but reveals wider variation in the measurement and effects of network dimensions. Recognizing this pattern, some scholars advocate an explicit distinction between networks and informal control. We formally address that issue with analysis of the measurement structure of multiple network and informal control indicators using data collected in 300 Seattle neighborhoods. Results reveal several distinct network dimensions that are themselves distinct from informal control. Regression analysis supports the systemic model: informal control reduces crime victimization, and networks exhibit an indirect, negative effect through informal control. Consistent with prior research, some network measures have a positive, direct effect on crime. We conclude that a distinction between networks and informal control is essential when testing and evaluating the systemic model.