In written responses to the House Committee on Natural Resources obtained by NPR, Major Adam DeMarco of the D.C. National Guard said he was copied on an email from the Provost Marshal of Joint Force Headquarters National Capital Region. He was looking for two things: a long range acoustic device, a kind of sound cannon known as an LRAD, and a device called the Active Denial System, or ADS.
The ADS was developed by the military some twenty years ago as a way to disperse crowds. There have been questions about whether it worked, or should be deployed in the first place. It uses millimeter wave technology to essentially heat the skin of people targeted by its invisible ray.
In his written response, DeMarco, who has sought whistleblower protection, quoted from an email he said was forwarded to him that originated from the Provost Marshal which read, the “ADS can provide our troops a capability they currently do not have, the ability to reach out and engage potential adversaries at distances well beyond small arms range, and in a safe, effective, and non-lethal manner.”