Which groups and individuals influence policy through their political activities? Criminal justice policy, because it is made at the local level, is often excluded from the study of interest group politics. In this paper, I provide evidence that senior citizens operate as a pro-police interest group at the city level. First, I show that senior citizens' attitudes are much more pro-police than their younger counterparts, even within the same race groups. Second, I show that cities with a greater share of residents 65 or older have larger and better-funded police departments, all else equal. These results have important implications for the study of interest groups, racial and ethnic politics, and criminal justice policy.