The Pentagon has given the Department of Homeland Security permission to test a military-grade heat ray and develop tactics, techniques and procedures for potentially using it in operations at the southern U.S. border, according to a memo signed by Defense Secretary Pete Hegseth last month and obtained by CNN.
The system, officially known as the Active Denial System (ADS), is a nonlethal directed-energy weapon. It fires an invisible beam of electromagnetic waves that the U.S. military says can reach a little more than half a mile.
How the heat ray works
When the beam touches skin, it creates an intense burning sensation. Pentagon officials have compared the feeling to the blast of heat from opening a hot oven. The military says the effect creates an instinctive, irresistible urge to move away from the beam, and that the tingling sensation can last between 10 and 15 minutes. Because it disperses people without projectiles, the military classifies the system as nonlethal.
According to the reporting, the memo authorizes a temporary loan of one ADS system to DHS for seven months, beginning in September. DHS — not Pentagon personnel — is responsible for operating it and for developing how it would be used.
Why it is controversial
Using the system at the border would be unprecedented. Current and former Customs and Border Protection officials say using the heat ray for crowd dispersal along the U.S.–Mexico border has been discussed internally for years but never adopted. Officials also considered deploying it during domestic unrest at the end of Trump’s first term, following the protests over the murder of George Floyd, according to a former official familiar with those discussions.
The DHS request reported by CNN did not specify where or how the system would be tested, or exactly how it might eventually be used. A DHS public affairs official said CBP continually evaluates new technology that can save lives while improving national security effectiveness.
What to watch
The seven-month evaluation is the key fact. Testing and writing tactics is not the same as deploying the weapon against people at the border — but it is the step that would have to come first, and it is now officially approved.
Sources: CNN reporting (October 21, 2026) on the Hegseth memo; U.S. military descriptions of the Active Denial System.
