The Pentagon has loaned Homeland Security a military heat ray for testing, with possible use for crowd control at the southern border

The system is called the Active Denial System. It fires a beam of electromagnetic waves a little more than half a mile. On skin it produces a burning sensation that military officials have compared to opening a hot oven. The effect, described by the Pentagon as a tingling that lasts 10 to 15 minutes, produces what officials call an instinctive and irresistible urge to run from it. It is classed as a nonlethal weapon.

The memo, signed by Defense Secretary Pete Hegseth last month and obtained by CNN, authorizes a temporary loan of one system for seven months starting in September, for testing and for developing tactics. It states the system shall not be operated by Defense Department personnel, a clause that leaves the operation, and the responsibility for it, with Homeland Security.

The Homeland Security request did not say where the testing would happen or how the weapon would eventually be used, CNN reported. Current and former Customs and Border Protection officials told CNN the idea of using the system for crowd dispersal along the Mexico border has been discussed internally for years. Officials also considered deploying it during domestic unrest at the end of President Trump first term, after the murder of George Floyd, according to a former official.

No American border agency has ever fielded the system. A test program is not a deployment, and the memo covers testing and tactics only. But a loan with a start date, a term and an operator restriction is a step past discussion, and any move from testing to operations at the border would be a first in American law enforcement.