Here is more from US Department of Justice:
United States Attorney Duane A. Evans today announced Russell Vennell, age 59, of Jefferson Parish, Louisiana, was charged on July 1, 2021 in a one-count indictment by a federal Grand Jury with making threatening phone calls in violation of Title 18, United States Code, Section 875(c).
According to previously filed court documents, on June 13, 2021, at approximately 2:08 a.m., a person called the Brookings Institution in Washington, DC 20036, from a telephone number found to be subscribed to Vennell. The caller stated that he was going to kill S.H., a person employed by the Brooking Institution at the time of the call. The subject later left a voicemail, at the Brookings Institution, reiterating the previous threat he made to kill S.H. Vennell was arrested on June 18, 2021 by agents of the Federal Bureau of Investigation.
If convicted, Vennell faces a maximum penalty of five (5) years imprisonment, followed by up to three (3) years of supervised release, up to a $250,000.00 fine, and a mandatory $100 special assessment fee based on the charge outlined in the indictment.
According to NOLA.com, Vennell apparently said "I'm going to wipe the entire Brookings Institution off the face of this f****** Earth. You are scum sucking evil (expletives) and you all deserve death in the most heinous way and it's coming at you."
This is not the first time that someone has wished ill upon Brookings. President Richard Nixon ordered his top aide to break into Brookings and steal its files on Vietnam. The plan involved firebombing the think tank.