H.R. 4403 would require the Department of Homeland Security (DHS) to establish performance metrics and milestones for the Securing the Cities (STC) program. STC provides funding to reduce the risk of radiological or nuclear attacks against major metropolitan areas in the United States by providing detection equipment, training, and operational support to local governments. H.R. 4403 also would require DHS, within two years of enactment, to submit a report to the Congress evaluating the performance of the program. In 2023, DHS allocated $35 million to the program.