In the earliest days of COVID-19, little was known about how the disease was spreading and whether it would lead to a global pandemic. Even as public health agencies began developing projections for the potential impact on general populations, public safety agencies needed more evidence to direct their response to the crisis. How could they develop policies to maintain essential first responder and patrol activities while also keeping officers safe from the disease? Shortly after the U.S. entered lockdown, our teams began to identify the specialized risk factors that police officers face to model the potential spread of COVID-19 among departments. These early projections alerted our partners in Chicago and New York to the pandemic’s potential impact and likely length, enabling both departments to protect better the well-being of their officers and the safety of their communities as public health conditions rapidly evolved.