Kennedy has been a leading voice in spreading false information about vaccines, scientists and public health leaders, often using heated rhetoric that says they have caused mass death and injury. People he describes in such language have said his comments have led to threats, intimidation and even violence.

Four CDC workers, who were not authorized to speak publicly, told CBS News under the condition of anonymity that they were "deeply disappointed and frustrated" by an apparent lack of leadership following Friday's shooting​.

By Dan Levine and Robin Respaut NEW YORK (Reuters) -Grappling with the aftermath of a shooting that killed a police officer and left nearly 100 shattered windows, leaders at the Centers for Disease Control and Prevention held virtual meetings with employees on Tuesday to rebuild trust at the agency's Atlanta headquarters.