Active Denial System
A US Marine Corps truck is seen carrying a palletized version of the Active Denial System. Getty Images

The U.S. might start using a heat ray to drive off migrants at the southern border, according to a new report.

The Pentagon is allowing the Department of Homeland Security to use the military-grade weapon at the border, CNN detailed. Officials describe the weapon as non-lethal.

The Active Denial System shoots an invisible beam of electromagnetic waves and can hit targets about a half mile away. Officials say that the weapon won't cause permanent injuries, but those hit by the heat ray will feel a "tingling" effect for several minutes.

"The Active Denial System is a counter-personnel, non-lethal, directed energy weapon. Traveling at the speed of light, the energy strikes the subject and only reaches a skin depth of about 1/64th of an inch," the Air Force states. "It produces a heat sensation that within seconds becomes intolerable and forces the targeted individual to instinctively move."

The ADS was deployed in Afghanistan and has been considered for use in crowd control situations. But it has never actually been used in a theater of operations. One analysis speculated that the weapon system has limitations, particularly in poor weather: rain, fog, mist, or snow. Also, its usefulness is limited to very specific scenarios.

The memo granting permission to use the military weapon for domestic border enforcement states that the system is on "temporary loan," CNN reported. It also states that the weapon would not be "operated by DoW (Department of War) personnel."

The memo included no details on how the weapon would be used.

A former Customs and Border Protection officer wondered whether the deployment would be worth it. "Even if they're chasing people back to the river, you don't want them to go in and drown," the official told CNN. "For the cost, for the training and for the policies you're going to create, is the juice worth the squeeze?"

A former DHS official questioned the appropriateness of using a military weapon on civilians. The official told CNN they had previously been part of such discussions.

"The issue was treating immigrants and citizens like enemy combatants," the former DHS official told CNN. "Thematically, inhumane treatments typically get rejected."