In Cohen and Felson's (1979) routine activities theory, the presence of a capable guardian serves as the key component in the crime event model, one that can disrupt, either directly or indirectly, the interaction between a motivated offender and a suitable target. Unlike the other components of the theory much less is known about the nature of capable guardianship. This article reports the results of a test of the Guardianship in Action instrument, first developed by Reynald (2009), for measuring guardianship potential at residential properties. It was found that guardianship intensity at the property level can be measured via direct observation, and the measurement of guardianship intensity is enhanced by including measures of the physical and social environment that can enable or hinder guardianship activities. The article lends further support to the thesis that residential guardianship combines physical potential for guardianship as well as acts of monitoring and intervention. The implications for theory, research and practice are discussed.