By Charlie Johnson & Ian Feldman
Program Manager, & Assistant Program Manager, Securing the Cities program in Houston
As a police officer drives through a neighborhood, he hears someone shouting, “Help! Help!” It could be benign, such as kids playing in their yard, shouting to their siblings to help them tackle their father. But it could also be a cry for help, that someone is being attacked, where that officer needs to step in to protect that person. The officer doesn’t know which scenario is playing out until he investigates.
Now imagine that that same officer has a device that detects radioactive materials. There are legitimate uses of radiation, such as construction, industry, and medicine. But radiation used improperly can also present a threat to the public, whether through negligence, regulatory violations, or criminal or terrorist acts. The only way that officer can determine whether a radiation alarm is legitimate is through investigation.
That detection capability exists today and is being actively deployed across the state of Texas. This article is meant to introduce prosecutors to this program, explain how it operates, respond to common legal questions about it, and address the fact that no caselaw yet exists in this area.
Securing the Cities program
In 2015, the City of Houston was awarded funding through the U.S. Department of Homeland Security’s Securing the Cities (STC) program. This cooperative agreement is intended to build preventative radiological/nuclear detection (PRND) programs across the United States. Funding provides training and equipment to public safety professionals to give them the knowledge, skills, and abilities to both detect radiation and determine if that radiation poses a hazard to the public. In addition to Houston, there are 12 other regions across the country receiving this funding.
The program relies on common operating policies among all participating agencies, which are based on national standards authored by the Department of Homeland Security (DHS), Federal Bureau of Investigation (FBI), and U.S. Department of Energy (DOE). Training also follows national guidelines and is conducted under the authority of the Federal Emergency Management Agency’s (FEMA’s) National Training and Exercise Directorate. Equipment must meet ANSI (American National Standards Institute) standards to ensure reliability and applicability to the program’s mission. As the STC program is a cooperative agreement, staff at DHS’s Countering Weapons of Mass Destruction (CWMD) office are closely involved in local programmatic decisions, ensuring compliance with all these requirements.
Initial partners for the STC program in Houston were agencies in a five-county region around Houston. All participants signed on to a single Operations Plan and Concept of Operations, and all received standardized equipment and training. Since that time, DHS granted approval for the program to expand across Texas, working through the Texas Highway Patrol, FBI-recognized bomb squads, and key cities. That expansion process uses the same standardized model as the program’s original deployment.
Real-world radiation incidents
Radiation is all around us every day. We are constantly exposed to very low levels, called background radiation, which comes from a variety of natural and human-created sources. But radiation is also used in multiple fields, most commonly medicine, construction, and the oil and gas industry. This means that radioactive material (often referred to as “source” or “sources”) are present in industrial devices, they are used for medical treatments, and they are transported by commercial shippers and private couriers across Texas. While proper handling normally ensures these sources are safe for the public to be around, they are all still emitting radiation that can be detected, even at a distance.
In October 2023,[1] a Houston Police Department (HPD) officer who was equipped with a radiation detection device was driving to work when his radiation alarm went off. The officer’s initial thought was that the alarm was triggered by an industrial source in the same area, but when the alarm went off in the same location on his return trip and again on subsequent days, he opted to exit the highway to further investigate, successfully identifying the source of the alarm as a scrap metal facility. Following his training, the officer requested assistance from the HPD Bomb Squad, who located several abandoned radiological sources, including one which was unshielded. These sources had been sent from the original industrial owner for processing as hazardous waste product. Material tracking shows that it changed ownership several times and at some point, was lost from regulatory control and ended up in this scrapyard. Because the owners of this yard had just purchased the venue at a tax auction, they were not charged for the recovery costs. Had these sources been taken by a malicious actor, they could have been turned into a radiological exposure device or a radiological dispersal device (“dirty bomb”), but fortunately, the material was recovered and safely removed. Based on available data, this was the largest recovery of material outside of regulatory control that authorities did not previously know was missing.
In July 2024,[2] first responders in Rankin (in Upton County) received reports of an oilfield truck that had caught fire. The truck had a radioactive source mounted inside a density gauge
used during hydraulic fracturing, and responders were concerned about effects of the fire on the source. The Radiological/Nuclear Detection Unit from Texas’s Department of Public Safety responded with two Commercial Vehicle Enforcement (CVE) corporals equipped with advanced detection equipment. These corporals assessed the area for hazards and determined the source had remained intact, responders had not been exposed to any harmful levels of radiation, and the area had not been contaminated. The corporals also served as liaisons between local responders and subject matter experts, ensuring that the incident commander had sufficient information to properly resolve the scene.
Both situations were successful because of the policies, training, and equipment provided through the Securing the Cities program and its partners.
Primary screening
Most of the STC program’s activities rely on officers, deputies, and troopers who have been trained on and equipped with personal radiation detectors (PRDs), which are body-worn devices capable of detecting gamma radiation. Unlike chemical or biological weapons, radioactive sources can easily be detected at a distance because they are constantly emitting radiation. That radiation moves at the speed of light, passing through intervening objects to reach the detector, making this a passive detection process. If the radiation levels increase above pre-set thresholds, the PRD alarm indicates that radiation was detected. Using the training they received prior to issuance of the PRD, the operator then investigates to verify the alarm, locate the source, and validate whether the cause is legitimate or illicit. This process is known as “primary screening.”
In the overwhelming majority of cases, officers determine that the alarm is due to a legitimate source. In the Houston region alone, there are over 100,000 radiopharmaceutical procedures per year. For example, one of the most common procedures is the use of Technetium-99, a short-lived radioactive material cardiologists inject into patients to aid in imagery of the heart and potential blockages. Additionally, the Texas Department of State Health Services (DSHS) reports that there are at least 1,200 licensed pieces of equipment used in road construction that contain radiological sources and more than 500 portable radiological sources used for non-destructive testing (NDT). NDT is a common practice of inspecting high stress building materials and aircraft parts by using radiography (similar to dental X-rays, just stronger) to inspect welds for inconsistencies like small air bubbles that could weaken the material. Both of these industrial devices are commonly transported by road and used all over Texas. The officers’ training provides them with sufficient knowledge to resolve these situations without additional assistance.
Secondary screening and technical reachback
However, there are times where an officer cannot resolve a radiation alarm solely through primary screening. In those cases, the officer requests an operator with additional training and a Radio-Isotope Identifier Device (RIID), which can analyze the radiation to determine what specific isotope is present. Knowledge of the specific isotope (which cannot be determined by a PRD alone) assists in the process, as that information can be compared with Department of Transportation (DOT) shipping papers, medical documentation, or other information to verify whether the presence of radiation is legitimate or illicit. This process is called “secondary screening.”
Bomb squads and hazmat teams perform secondary screening because of their increased knowledge of the prevention and detection missions, as well as their ability to perform response operations if the source presents a danger to the public. Examples of a response operation could include recovering an abandoned source, mitigating radioactive contamination, securing malfunctioning industrial equipment, or rendering safe a terrorist weapon. These units regularly work with the FBI’s WMD Directorate, ensuring smooth cooperation with federal authorities should terrorism be suspected. Note that there may be a time delay before secondary screening can take place, as the bomb tech or hazmat tech may have to travel a greater distance, including potentially from a different jurisdiction.
Secondary screening is also supplemented by a validation process known as “technical reachback.” After the RIID displays the isotope information, if additional confirmation is needed, that data can be sent electronically to Department of Energy scientists who perform additional analysis on the data, helping further refine the resolution process. If a terrorist weapon is suspected, the scientists also provide data on the packaging and shielding of the weapon that is valuable to the bomb squad in rendering the device safe.
Legal authorities and legal questions
During the STC program’s kick-off phase in Houston, staff met with representatives from prosecutor offices from the five initial program counties to brief them on the program’s activities and answer their questions about the PRND mission. The conversations covered the following questions and answers:
Is there a specific radiation “threshold” for whether a source of radiation is legitimate or illicit? No, because of the science behind radiation and radiation detection, the level of radiation does not equate to the level of threat.
The level displayed on a meter is impacted by distance and shielding, so the same source can have different readings depending on how close the detector is and what is in between the source and the detector. The level also has no bearing on how the material is being used, only that it is present.
Consider three cases: a medical patient who has received a nuclear stress test, a source projector used in non-destructive testing (NDT), and a nuclear weapon. Depending on factors such as distance from the source and whether shielding is present, each of these can cause the same readings on a radiation detector. The medical patient does not pose a threat from the radiopharmaceutical treatment he has undergone. The NDT source projector is a commonly used industrial tool if operated safely but poses a great health hazard if used improperly (such as the case of Jared Atkins in Phoenix in 2019[3]). And a nuclear weapon has the potential for catastrophic impact.
It is only through an operator’s investigation of the initial radiation alarm and considering the totality of the circumstances, potentially with the assistance of secondary screening, that a formal determination of “threat” versus “no threat” can be made.
Do the detectors require calibration? PRDs do not require regular calibration, though other radiation detection equipment may, depending on its use. Because the readings displayed on a PRD do not equate to the level of threat, the exact measurement is not relevant to the primary screening process, so long as a PRD successfully indicates levels above normal background. Further determination relies on the officer’s investigation, not the device’s displayed levels.
This differs from speed detection, where there is a legal limit for vehicle speed. In this case, the device must reliably differentiate between speeding and acceptable speed, and calibration is necessary.
Radiation detection equipment used in a regulatory capacity (such as items carried by DOT commercial vehicle inspectors) is regularly calibrated because unlike primary screening, regulatory inspections do involve actionable levels of radiation. Similarly, RIIDs contain internal self-calibration technology to ensure they can reliably identify isotopes.
Are there any special cases that could cause a false radiation detection from a person? Officers are trained on procedures to verify alarms and localize those alarms to a person, package, or vehicle.
Alarm verification involves ensuring that an alarm is repeatable, which can be done by having a second officer with a PRD confirm the alarm or allowing a PRD to reset to background and then re-approaching the source to verify that the alarm is legitimate.
Officers are trained to separate people from packages, vehicles, and groups. There is no situation where two non-radioactive items or people would generate radiation only when in close proximity, so separation allows the officer to localize the alarm to a specific person, vehicle, or item. The training provided by STC in Houston specifically emphasizes the need for discretion in this process to not inadvertently reveal that an individual may have received a medical treatment to others in the area, ensuring the privacy of the subject remains intact.
Certain industrial uses of radiation can result in intermittent PRD alarms, caused by the fact that powerful sources are moved into an unshielded position during use and then back into a shielded position for transport. Again, training is designed to ensure that officers are aware of these situations, and in these cases, equipment operators will have licenses and documentation for their industrial sources.
What laws and case history are present on radiation detection? Texas Health and Safety Code §401.101 restricts who can possess, transport, etc., radiation sources, and violations are a Class B misdemeanor unless that person has a license from DSHS or meets an exception under the rules (such as medical patients). However, there is no caselaw on arrests or stops based on radiation, either in Texas or elsewhere in the United States.
The presence of radiation meets the definition of reasonable suspicion to stop and investigate, as state law makes the possession or transport of radiological materials illegal, and the radiation detector confirms that those materials are present through a passive process. An officer cannot determine if an individual falls under an allowed use of radiation under the law without stopping that individual for further investigation, which potentially includes a field interview, asking to review documentation or licensure, or using context clues to determine the totality of the circumstances.
This differs from other legal situations. It is not like requesting a narcotics canine because in that case, the original officer only suspects that someone has illicit drugs and requests the canine to confirm this via a search. It also differs from using an infrared camera which intentionally looks through barriers that would otherwise provide privacy, whereas the radiation detector is responding to radiation that has left someone’s person or property and is now in a public area when it reaches the detector.
What steps are being taken to legally secure the program and its activities? Because there are no court cases within the state or nationally that establish caselaw for radiological/nuclear investigations (for example, how long can a person be detained while awaiting a secondary screener to arrive) the STC program has established several processes that should aid in prosecution as well as defend the actions taken by officers who would likely be challenged by defense attorneys.
The program relies on national standards for policies, training, and equipment, and DHS monitors this and ensures that funding is not provided if these standards are not upheld.
Programmatic reporting mechanisms are in place. Primary screening interactions are voluntarily reported by the officers who receive radiation alarms to track them, because most of those interactions do not involve any legal violations and therefore do not generate offense reports. The DHS grant program also requires that secondary screening be reported for tracking and situational awareness purposes. This data is compiled both within the Houston region and at the national level.
The STC program in Houston assists participating agencies with offering regular refresher training, designed to provide hands-on, scenario-based drills based on the types of real-life radiation alarms officers have reported encountering in the field. And policies and training are validated through periodic tabletop and functional, full-scale exercises.
Agencies perform regular in-house verifications that the provided detection equipment is functioning within normal parameters, and the STC program in Houston will replace any damaged or defective equipment at no cost to the agency and no penalty to the officer to whom the equipment is issued. The Houston program also periodically trades out equipment and subjects it to more formalized validation processes to verify it remains within manufacturer standards.
If secondary screening is necessary, there may be a time delay while the bomb tech or hazmat tech responds to the scene. Agency personnel are instructed to follow all existing procedures for holding subjects during this interval. For example, if an agency policy necessitates securing the subject in the back of the patrol car during this interval for officer safety purposes, then that process should apply here as well. But if an agency does not allow this, then the officer must follow whatever policy exists on the topic.
When caselaw will be created in the future
Ultimately, we in the STC program do not believe that caselaw will be set, either in Texas or elsewhere, through a terrorism-related arrest. Instead, consider the following scenario:
An officer is assigned a post at a special event where there is elevated security. Someone carrying a backpack approaches the post, and the officer’s PRD begins to alarm. The values on the PRD increase as the individual walks up to the officer, and those values decrease after the individual has walked past. There are no other individuals or vehicles in the area, so based on this information and his training, the officer can reasonably determine that the individual or his belongings are emitting radiation.
Given the heightened security related to the special event, the officer leaves his post to approach the person and investigate the radiation alarm. The radiation levels on the officer’s PRD increase again as the officer gets closer to this person, further confirming that individual or his belongings are the source of the radiation. The officer now must try to determine if the source is legitimate by speaking with the subject.
The officer stops the person, introduces himself, explains that the PRD indicated the presence of radiation, and asks if there is any reason radiation would be present on his person or belongings. Because the vast majority of radiation alarms are legitimate, giving the individual the ability to explain the presence of radiation at the beginning of the interaction will usually lead to faster resolution and put subjects more at ease. The individual confirms he recently underwent a radiopharmaceutical treatment. The officer separates the individual from his belongings, and using the PRD, confirms that the radiation is coming from the person and not the backpack. This process rules out a “masking” situation, eliminating the possibility that the person is also carrying an illicit device in addition to being a (legitimate) medical patient.
To be thorough, the officer asks the person if he has any documentation of the medical procedure, and the individual confirms that he does. But as the man pulls documentation from his pocket, a bag of drugs also falls out and lands on the ground. The drugs are now in plain view, and the officer arrests the individual for possession of a controlled substance. The local district attorney’s office accepts the charges, and the subject is taken to jail.
The subject’s defense attorney will then do her best to protect her client. The drugs were found in plain view, so there is no search to challenge in court. Instead, the defense attorney would challenge the chain of events leading up to those drugs falling from the subject’s pocket. In this case, the underlying reason for the stop (and the inadvertent dropping of the bag of drugs) was the radiation alarm itself. As such, this is the type of scenario the STC program expects will end up creating caselaw in this area.
To bolster the program, STC staff in Houston are prepared to assist in cases like this. Program staff can provide documentation on policies, training, and equipment showing that officers can perform radiation detection activities and resolve most alarms without further assistance. The documented alarm histories voluntarily provided to the STC program can illustrate how the program operates without infringing on civil liberties and that radiation alarms are not used for pretext stops. And program staff can provide expertise on radiation detection should technical questions arise. We hope to ensure successful prosecution in a case such as this, thus creating caselaw that supports preventative radiological or nuclear detection programs.
About the authors
For any questions or follow-up issues or to arrange a virtual meeting with other staff from your office to further discuss the program, please do not hesitate to reach out to our office via email at [email protected] or via phone at 832/393-0938.
The STC Program Manager, Charlie Johnson, has been with the program since its inception in 2015. Prior to that, he worked for the Houston Police Department for over 30 years, retiring as the sergeant over the bomb squad. During his time with HPD, Charlie also served on an HPD/FBI/DOE task force that was trained and had the clearances necessary to perform render-safe actions on radiological dispersal devices and nuclear weapons.
The STC Assistant Program Manager, Ian Feldman, has been with the STC Houston program since 2022. Prior to that, he worked on a regional critical infrastructure protection program in southeast Texas. Outside of his work with the City of Houston, he is a paramedic, firefighter, and hazardous materials technician. His educational background is in emergency management and homeland security.
As part of the statewide expansion of the STC program, the Texas Department of Public Safety has stood up a specific Radiological/Nuclear (Rad/Nuc) Detection Unit under the Texas Highway Patrol’s Commercial Vehicle Enforcement division. Staffed by a lieutenant, sergeant, and six corporals deployed across the state, the DPS Rad/Nuc Detection Unit is the lead group within DPS for training and operational support. In addition, the unit has assisted local agencies, the FBI, and the 6th Civil Support Team with detection activities at major special events across the state.
[1] www.houstonchronicle.com/news/houston-texas/environment/article/radiation-houston-police-dirty-bombs-18516329.php.
[2] www.dps.texas.gov/news/dps-responds-fire-involving-radioactive-materials.
[3] www.justice.gov/usao-az/pr/phoenix-man-sentenced-15-years-planning-release-stolen-radiological-materials-scottsdale.