The CIA, Department of Defense and Air Force declined to comment.
A CIA spokesperson said law enforcement responded to an "incident" outside CIA Headquarters, located in Fairfax County.
The CIA became the first major national security agency to offer so-called buyouts to its entire workforce, a CIA spokesperson and two other sources familiar with the offer said, as part of President Donald Trump's broad effort to shrink the federal government and shape it to his agenda.
Since launching in 2021, America First Policy Institute has been known colloquially around Washington, D.C., as Donald Trump's "Cabinet in waiting."
The lawsuit alleges the FBI, CIA and NYPD conspired in the activist's assassination in 1965 and engaged in a decades-long coverup.
Retired CIA and FBI officials offer insight into how the agencies conduct intelligence gathering.