Pentagon clears DHS to test Active Denial System heat ray for border use

The Pentagon has given the Department of Homeland Security permission to test a military-grade heat ray and develop tactics to potentially use it in operations at the southern US border. The permission is in a memo signed by Defense Secretary Pete Hegseth last month, which CNN obtained.

The weapon is officially called the Active Denial System. According to the US military, it is a nonlethal weapon that shoots an invisible beam of electromagnetic waves, which can reach a little more than half a mile. On contact with human skin the beam causes a burning sensation, which Pentagon officials have previously compared to the blast of heat you feel when opening a hot oven. Military officials have said the "tingling effect" lasts between 10 and 15 minutes and also produces "an instinctive and irresistible urge to run from the effect."

The memo authorizes a "temporary loan" of one ADS system for seven months, starting in September. It says the system "shall not be operated by DoW (Department of War) personnel," which CNN reads as appearing to absolve the Pentagon of responsibility for how the system may ultimately be deployed. It also says DHS is solely responsible for "system employment, use and development of tactics, techniques and procedures." At the end of the loan, DHS can submit an additional request for further use of the system in border operations based on need, a defense official told CNN.

The DHS request did not specify where or how the weapon would be tested or how it might eventually be used. CNN calls deploying the heat ray at the border an unprecedented step, even for the Trump administration, which has made border security and immigration a top priority. Current and former Customs and Border Protection officials told CNN there have been internal discussions over the years about using it for crowd dispersal along the US-Mexico border. A former US official familiar with the talks said officials had also considered using it during domestic unrest, including at the end of Trump's first term when protests erupted over the murder of George Floyd. A CBP spokesperson said in a statement: "CBP is continually evaluating new technologies, especially those that enhance operational effectiveness and strengthen mission capabilities." The Pentagon referred CNN to DHS when asked for comment.

The system has a history of not being used. The US military briefly deployed it to Afghanistan nearly two decades ago but ultimately declined to use it in active combat operations. A source familiar with internal considerations said the military also weighed it for crowd control at facilities abroad holding terrorist detainees, and declined that too. Border officials have occasionally discussed it as a crowd dispersal tool, including for areas with a high concentration of illegal crossings, but it has never been deployed.

Officials ran into hurdles over legalities, use of force, effectiveness, and possible sovereignty problems, particularly if the system were used on people in Mexico who had not yet crossed into the US. Chief among the concerns was whether people could be harmed, directly or indirectly. A former CBP official told CNN: "Even if they're chasing people back to the river, you don't want them to go in and drown. For the cost, for the training and for the policies you're going to create, is the juice worth the squeeze?"

The El Centro sector, which covers around 70 miles of the border, evaluated the system several years ago, when Rodney Scott, now CBP commissioner, led that sector, according to a CBP official. Officials then discussed whether it could discourage people from crossing the nearby river or push them out of the water, and whether it might lead to more rescues if people were incapacitated by it. It is unclear why it was not deployed there. In 2018, before the midterms, CBP officials weighed using it against migrants, but then-Homeland Security Secretary Kirstjen Nielsen shot it down. A former DHS official familiar with those discussions said: "The issue was treating immigrants and citizens like enemy combatants. Thematically, inhumane treatments typically get rejected." Another former CBP official said some Border Patrol agents have more recently doubted they need the tool at all, given low border crossings and an increase in personnel.

Key facts

A memo signed by Defense Secretary Pete Hegseth last month, obtained by CNN, lets DHS test the Active Denial System and develop tactics to potentially use it at the southern US border.
The memo authorizes a temporary loan of one ADS system for seven months, starting in September; DHS can then submit an additional request for further use based on need.
The military says the nonlethal beam reaches a little more than half a mile and causes a burning sensation; officials say the tingling lasts 10 to 15 minutes and produces an urge to run.
The memo says Pentagon personnel will not operate the system and that DHS alone is responsible for its employment, use and tactics.
The system has never been deployed at the border; past talks stalled over legality, use of force, effectiveness, sovereignty and the risk of harm, and in 2018 then-DHS Secretary Kirstjen Nielsen rejected using it on migrants.

Why it matters

CNN describes using the heat ray at the US border as an unprecedented step, even for an administration that has made border security a top priority. The Active Denial System is a military weapon that has not been used in combat: the US military briefly deployed it to Afghanistan nearly two decades ago but declined to use it there, and it has never been deployed at the border. The memo moves it from internal discussion to an authorized test and tactics development by a civilian agency.

Who it affects

DHS and Customs and Border Protection are the direct recipients and are solely responsible for how the system is employed. The people who could be affected are those at the southern border; officials in past discussions raised the case of people in Mexico who had not yet crossed into the US. The Pentagon has stepped back from responsibility for deployment: the memo bars Department of War personnel from operating the system, and the Pentagon referred CNN's questions to DHS.

How to use it

This is not a product anyone can adopt; it is a loan arrangement. The memo covers one ADS system for seven months starting in September, with DHS handling employment, use and development of tactics, techniques and procedures. After the loan period, DHS can submit an additional request for further use in border operations based on need, a defense official told CNN. Where and how testing will happen has not been specified.

How solid is it

The core facts rest on a memo signed by Hegseth that CNN obtained, plus a defense official on the follow-on request process. Descriptions of the weapon's range and effects come from the US military and Pentagon officials. The history of internal discussions comes from current and former CBP officials, a former US official and a former DHS official, none named. The DHS request did not specify where or how the weapon would be tested or used. Only a general CBP statement was given on the plan, and the Pentagon referred CNN to DHS.

Risks and caveats

Past discussions ran into concerns about legality, use of force, effectiveness and sovereignty, with harm to people, direct or indirect, the chief worry. A former CBP official gave the example of people being driven back toward a river and drowning, and asked whether the cost, training and policy work are worth it. A former DHS official described the 2018 objection as treating immigrants and citizens like enemy combatants. Some Border Patrol agents have recently doubted they need the tool at all, according to another former CBP official. A test authorization is not a decision to deploy, and how DHS will actually use the system is not stated.

“The issue was treating immigrants and citizens like enemy combatants”

— A former DHS official familiar with previous discussions about using the weapon against migrants, speaking to CNN