 and certainly we need to make sure that something like this doesn't happen again. Iowa Senator Chuck Grassley launched a multi-pronged investigation in the wake of Trump's attempted assassination. A senior member and former chairman of the Senate Judiciary Committee, Grassley sent letters to the U.S. Secret Service, FBI, and the Departments of Homeland Security and Justice, as well as the Homeland Security Inspector General, requesting records and responses regarding what's been deemed a security failure Saturday.