AbstractPolicy process theories posit that focusing events can trigger significant shifts in public attention and policy preferences, thereby reshaping public agenda setting. Prior studies, however, have not clearly defined the scope of public opinion changes induced by these focusing events, leading to inconsistent empirical findings. This study aims to reconceptualize the multiple layers of public opinion and formulate testable hypotheses to investigate the causal effects of a major focusing event—the 2016 Orlando nightclub mass shooting—on public opinion. Using original and unique survey data collected immediately pre‐ and post‐Orlando shooting, we find that this event significantly heightened public attention to terror‐related issues, particularly armed terror attacks on civilians. This increased attention translated into heightened support for augmented government counterterrorism spending. However, the event did not significantly alter public attention or support for government spending on other terror‐related acts less relevant to the Orlando shooting. Moreover, the event did not change individuals' policy preferences regarding specific policy proposals to address mass shootings. Our study enriches public policy and public opinion research and provides fresh insights into the relationship between focusing events and public agenda setting.