In this paper, we investigate the protective effect of smart street lighting on public safety. Smart lights have a variety of features, such as video surveillance or gunshot detection. Some of these features can have a deterrent effect on crime. Other features, however, such as adaptive brightness control, may also encourage crime. Using a comprehensive dataset on the crimes committed in downtown San Diego (CA) during 1st May 2017 and 30th April 2018, we investigate the crime rates a priori and posterior to the installation of smart lights in this area. The results of the empirical analysis suggest that smart lights have a statistically significant negative impact on crime and that their installation increases the safety of citizens.