DHS OIG, OIG-25-33, CBP Continues to Evaluate Cross-Border Tunnel Detection Technologies - (REDACTED) (2025)

FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE OIG-25-33 August 25, 2025 FINAL REPORT CBP Continues to Evaluate Cross-Border Tunnel Detection Technologies (REDACTED) FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE WARNING: This document is Law Enforcement Sensitive (LES). Do not distribute or copy this report without the expressed written consent of the Office of Inspector General. FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE OFFICE OF INSPECTOR GENERAL U.S. Department of Homeland Security Washington, DC 20528 | www.oig.dhs.gov MEMORANDUM FOR: FROM: SUBJECT: August 25, 2025 The Honorable Rodney S. Scott Commissioner U.S. Customs and Border Protection Joseph V. Cuffari, Ph.D. Inspector General CBP Continues to Evaluate Cross-Border Tunnel Detection Technologies – For Official Use Only//Law Enforcement Sensitive Attached for your action is our final report, CBP Continues to Evaluate Cross-Border Tunnel Detection Technologies – For Official Use Only//Law Enforcement Sensitive. The report does not contain recommendations.

CBP declined to submit formal comments. Consistent with our responsibility under the Inspector General Act, we will provide copies of our report to congressional committees with oversight and appropriation responsibility over the Department of Homeland Security. We will post a redacted version of the report on our website. Please contact me with any questions, or your staff may contact Craig Adelman, Deputy Inspector General, Office of Audits, at (202) 981-6000.

Attachment OIG Project No. 23-070-AUD-CBP FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE DHS OIG HIGHLIGHTS CBP Continues to Evaluate Cross-Border Tunnel Detection Technologies August 25, 2025 What We Found Why We Did This Audit U.S. Customs and Border Protection (CBP) continues to evaluate and obtain critical technology needed to identify, assess, breach, and remediate cross-border tunnels and has made progress in its efforts since our 2021 audit on border technology. The Department of Homeland Security in January 2020 and January 2024 approved testing by the Cross-Border Tunnel Threat program of two critical tunnel detection technologies to evaluate whether they are functional and viable solutions. At the time of this audit, these technologies were being tested for effectiveness in operational conditions and eventual vendor selection. Based on CBP’s progress, it was too early for us to audit the effectiveness of these technologies and therefore we made no recommendations.

We note, however, that once CBP selects its tunnel detection technology solutions, the program’s success will require adequate program resources and effective coordination between CBP offices. CBP Response CBP declined to submit management comments. CBP is responsible for enforcing U.S. laws pertaining to illegal immigration and narcotics smuggling. Within CBP, U.S. Border Patrol’s Cross-Border Tunnel Threat program is responsible for strengthening border security by diminishing the ability of transnational criminal organizations to enter the United States through cross-border tunnels.

We conducted this audit to determine whether CBP’s Cross- Border Tunnel Threat program has the technology to identify, assess, breach, and remediate cross-border tunnels. What We Recommend We made no recommendations. For Further Information: Contact OIG Public Affairs at (202) 981-6000 or [email protected]. www.oig.dhs.gov OIG-25-33 FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE OFFICE OF INSPECTOR GENERAL U.S. Department of Homeland Security Background U.S. Customs and Border Protection (CBP) is one of the world’s largest law enforcement organizations. CBP’s top priority is preventing terrorists from entering the United States while facilitating lawful travel and trade.

CBP’s mission includes safeguarding U.S. borders from threats, including those posed by transnational criminal organizations who seek to enter or harm the country using subterranean tunnels. 1 Illicit cross-border tunnels have long posed a threat to our Nation. Transnational criminal organizations use these tunnels to smuggle people, weapons, currency, and drugs, including synthetic opioids such as fentanyl. Between FY 1990 and FY 2023, 236 illicit cross-border tunnels , were discovered in the United States.

As of FY 2022, most tunnels discovered were in the area. 2 3 The Border Tunnel Prevention Act of 2012 requires the Department of Homeland Security to submit an annual report to Congress regarding “the needs of the Department of Homeland Security to effectively prevent, investigate, and prosecute cross-border tunnel construction along the border between Mexico and the United States.” More recently, Congress passed the National Defense Authorization Act for FY 2023, directing CBP to develop a strategic plan within 180 days of enactment to “promote the use of innovative technologies to identify, breach, assess, and remediate illicit cross-border tunnels.” The legislation also requires CBP to develop processes 7 to share relevant illicit cross-border tunnel locations, operations, and technical information. According to the 2023 Act, CBP must also produce a resource needs assessment that includes technology and staffing needs. In August 2023, CBP updated its Operational Requirements 8 5 6 4 1 Subterranean is defined as being, lying, or operating under the surface of the earth.

2 Border Tunnel Prevention Act of 2012, Pub.

L. No. 112-127.

3 As noted in the Pub. L. No. 112-127, this annual report shall be delivered to the following six committees: 1) the Committee on Homeland Security and Governmental Affairs of the Senate; 2) the Committee on the Judiciary of the Senate; 3) the Committee on Appropriations of the Senate; 4) the Committee on Homeland Security of the House of Representatives; 5) the Committee on the Judiciary of the House of Representatives; and 6) the Committee on Appropriations of the House of Representatives. 4 James M. Inhofe National Defense Authorization Act for Fiscal Year 2023, Pub.

L. No. 117-263, Section 7134.

5 Tunnel remediation is the process of physically securing illicit cross-border tunnels and rendering them unusable. According to Border Patrol, a fully remediated tunnel is safer, more secure, and less resource-intensive to monitor. Illicit cross-border tunnels can be remediated by filling the tunnel cavities with high-strength concrete, flowable grout solutions, or other materials. 6 This legislation also directs CBP to perform its cross-border tunnel work in a manner that, among other considerations, reduces the impact of such activities on surrounding communities.

James M. Inhofe National Defense Authorization Act for Fiscal Year 2023, Pub.

L. No. 117-263, Section 7134(a)(1)(B).

7 Id. at Section 7134(a)(1)(C). 8 Id. at Section 7134(a)(1)(E)(i)-(ii). www.oig.dhs.gov 1 OIG-25-33 FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE OFFICE OF INSPECTOR GENERAL U.S. Department of Homeland Security Document to detail the requirements necessary to close capability gaps in detecting illicit tunneling activity along the Southwest border. Within CBP, the U.S. Border Patrol (Border Patrol) has a broad mission that includes the detection, apprehension, and/or deterrence of terrorists and terrorist weapons. Border Patrol is also the lead law enforcement agency for subterranean missions.

In 2021, Border Patrol recognized the need for a dedicated subterranean mission–focused group and established the National Subterranean Operations (NSO) office within Border Patrol’s Law Enforcement Operations Directorate (Operations Directorate). NSO was designated as the lead office for countering cross-border tunnel vulnerabilities. NSO provides a centralized operational coordination point for subterranean missions along the U.S. border. Border Patrol’s Program Management Office Directorate’s (Program Management Office) Cross- Border Tunnel Threat (CBTT) program works with NSO to deploy sensor technology and material needs to predict, detect, confirm, investigate, exploit, and remediate targets related to suspected tunnels and underground activity.

The Program Management Office supports field operations by rapidly acquiring, deploying, and maintaining integrated solutions. Border Patrol has taken a cross-directorate approach to combat illicit tunnels (see Figure 1). In FY 2023, the Operations Directorate and the Program Management Office partnered with CBP’s Laboratories and Scientific Services to develop the proof of concept for a Tunnel Reachback Center (TRC). The TRC proof of concept is now operational and provides Border Patrol with sensor data analysis, scientific guidance, and on-demand deployable support for counter-tunnel operations.

Figure 1. Border Patrol Subterranean Operations Coordination www.oig.dhs.gov 2 OIG-25-33 FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE OFFICE OF INSPECTOR GENERAL U.S. Department of Homeland Security Source: DHS Office of Inspector General, based on Operations Directorate, NSO data, as of March 2024 In October 2023, CBP completed the Counter Illicit Cross-Border Tunnel Operations Strategic Plan and submitted that plan to Congress, as required by the National Defense Authorization Act for FY 2023. The plan addresses all requirements within the legislation, and includes five overarching goals: 10 9 1. Mature the Operations Directorate’s NSO organization with additional dedicated staff to increase mission responsiveness; 2.

Codify subterranean mission skillsets and develop cross-directorate policy; 3. Promote consistent funding for subterranean domain situational awareness; 4. Continue acquiring innovative technology to facilitate the identification, assessment, and remediation of tunnels; and 5. Maximize collaborative partnerships to create a whole-of-agency approach.

During our audit, the CBTT program staff and partners (noted in Figure 1) were testing tunnel detection technologies along the Southwest border to determine effectiveness in operational environments between ports of entry. The technologies are part of the CBTT program’s , which includes permanent “Persistent Surveillance Detection” systems and a “Mobile Detection Tunnel Toolkit.” According to CBP, the program will use these capabilities together to combat illicit tunneling and operations within existing tunnels. The CBTT program collaborated with DHS’ Science and Technology Directorate to develop the program’s approach to testing and evaluating tunnel detection technologies. The persistent systems are permanently installed along the border to CBP, these systems must provide actionable tunnel detection information .

The CBTT program plans to use the persistent systems . CBP regards a Additionally, an area may be . CBP’s CBTT program plans to use the persistent systems According to CBP, According . . 9 James M. Inhofe National Defense Authorization Act for Fiscal Year 2023, Pub.

L. No. 117-263, Section 7134(a)(1).

10 Id. at Section 7134(b)(1)-(2) authorizes $1 million for fiscal years 2023 and 2024 to carry out the development of the strategic plan and remediation operations of illicit cross-border tunnels in accordance with the strategic plan to the maximum extent practicable. www.oig.dhs.gov 3 OIG-25-33 FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE OFFICE OF INSPECTOR GENERAL U.S. Department of Homeland Security . CBP will also use the capabilities in other areas . . Program documents indicated the persistent systems can also . According to CBP, the persistent systems will integrate with CBP’s Common Intelligence Picture11 .

CBP’s mobile toolkit complements the persistent systems and be deployed as needed and The mobile toolkit can . The mobile toolkit is 12 Unlike data from the persistent systems, the mobile toolkit data . As of June 2024, the CBTT program planned to deploy the mobile toolkit to areas . The CBTT program also planned to deploy the mobile toolkit to areas During a 2021 audit, we found that a tunnel detection solution was delayed by a lack of available technology and border wall construction.13 We conducted this audit as a follow-on to our prior work to determine whether CBP’s CBTT program has the technology to identify, assess, breach, and remediate cross-border tunnels.

Results of Audit Border Patrol Is Assessing Technology to Support Its Subterranean Mission The CBTT program is determining the technology that best supports its need to identify, assess, breach, and remediate cross-border tunnels. For example, the program is assessing the 11 A Common Intelligence Picture provides CBP and its partners a common understanding of terrorist and criminal threats including their tactics, techniques, and procedures; their capabilities and vulnerabilities; and indicators regarding their potential courses of action. 12 The mobile toolkit’s capabilities include a 13 CBP Has Improved Southwest Border Technology, but Significant Challenges Remain, OIG-21-21, February 23, 2021. . www.oig.dhs.gov 4 OIG-25-33 FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE OFFICE OF INSPECTOR GENERAL U.S. Department of Homeland Security persistent and mobile systems mentioned earlier and determining which vendor-provided systems are best suited for operational conditions. In January 2020 and January 2024, DHS approved both the persistent and mobile systems chosen by the CBTT program to be evaluated for whether they are effective and viable solutions.

14 During our audit, CBP tested persistent systems from three vendors. As of February 2024, CBTT had implemented 5 miles of the persistent systems along the Southwest border , and . Installation of a sixth mile was completed on March 14, 2024. .15 As of The total costs for the six miles of persistent systems were approximately August 2024, the sixth mile had not yet undergone System Acceptance Testing due to physical security concerns for vendor contractors related to high levels of migration activity and network upgrades needed at the supporting port of entry. System Acceptance Testing for the sixth mile was tentatively scheduled for September 2024.

According to program officials, CBP will select and award a contract to one of the systems. According to CBP, during testing, vendors for 30 additional miles of the persistent 16 In August 2023, CBP published an updated Operational Requirements Document that detailed requirements necessary to close capability gaps in detecting illicit tunneling activity along the Southwest border. According to the document, the 6 miles of persistent system capability should be completed, and the CBTT program should have by the fourth quarter of FY 2024 to achieve Initial Operational Capability.17 During our audit, the CBTT program operated a prototype kit of all that make up the mobile toolkit and anticipated receiving for field deployment in the fourth quarter of FY 2024.18 Full Operational Capability , which CBP expects will be obtained by the for the mobile toolkits is described as first quarter of FY 2026. The persistent system’s Full Operational Capability requires deployment of 19 to be completed by the fourth quarter of FY 2030.

The persistent and mobile 14 DHS approved the two technologies at Acquisition Decision Event-2A, which is a decision point in the DHS Acquisition Lifecycle Framework. The purpose of Acquisition Decision Event-2A is to verify a potential acquisition has well-defined operational requirements; a balanced, effective, and achievable solution set; a complete lifecycle cost; and complete acquisition and support plans. 15 According to CBTT Program Lifecycle Cost Estimate Annual Update from March 2022. 16 System Acceptance Testing will evaluate vendor systems against contractual requirements.

17 Program documentation from 2019 indicated a previous Initial Operational Capability date of quarter one of FY 2021. Based on information provided by the CBTT program office in August 2024, the projected Initial Operational Capability date may be moved to FY 2025. This information was provided after our survey work concluded, so we were unable to assess any impacts. 18 Although CBP made progress identifying tunnel detection technologies since our 2021 report, it was too early for us to determine effectiveness during our survey work, in part because a final vendor had not been chosen for the persistent systems and the mobile toolkit technologies were operating as prototypes.

19 During our survey work, 6 miles were being tested, and 30 additional miles are expected to be deployed by the selected vendor. www.oig.dhs.gov 5 OIG-25-33 FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE OFFICE OF INSPECTOR GENERAL U.S. Department of Homeland Security systems will be deployed in areas of risk identified by CBP along the Southwest border. The mobile toolkits will also be operated along the Southwest border and provide flexibility to use the technology elsewhere. Figure 2 shows the CBTT program’s projected deployment timeline for its persistent and mobile systems. Figure 2.

Projected Deployment Timeline of CBTT’s Persistent and Mobile Systems20 Source: DHS OIG analysis of CBTT acquisition documents as of August 2023 Adequate Resources and Effective Coordination Will Be Needed to Implement CBP’s Counter Illicit Cross-Border Tunnel Operations Strategic Plan Once at Full Operational Capability, the subterranean operations will require appropriate funding, staffing, and other resources to be effective. The CBTT program and its partners must account for the unique challenges of the subterranean environment when resource planning. Border Patrol’s subterranean work is executed by multiple CBP directorates, including the Program Management Office, the Operations Directorate, and Laboratories and Scientific Services;21 each has its own resource needs to meet strategic plan goals. We determined the CBTT program and its partners’ staffing needs will increase as more persistent and mobile systems are deployed.

This will require continued coordination between CBTT stakeholders as the program matures. 20 Our survey work ended on April 17, 2024. However, we received additional clarifying information for context from the Department after the conclusion of our survey work. Any potential changes to CBTT’s projected deployment timeline following our survey work are not reflected in this report.

The program will formally baseline at the next step in the Acquisition Lifecycle Framework. 21 Laboratories and Scientific Services will support CBP’s tunnels mission until July 2025. www.oig.dhs.gov 6 OIG-25-33 FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE OFFICE OF INSPECTOR GENERAL U.S. Department of Homeland Security The CBTT Program Will Need Adequate Funding as the Program Progresses According to CBP, the estimated lifecycle cost for the CBTT program from FY 2017 to FY 2039 is .22 The program received $10.4 million in funding in the FY 2024 enacted budget23 but continued funding is necessary for the long-term success of the CBTT program. We note that the One Big Beautiful Bill Act, signed into law on July 4, 2025, provides over $6 billion to CBP for border security, technology, and screening efforts through FY 2029. Currently, the contract for one of the three persistent system vendors is contract for the other two systems is a total of procurement contract will be awarded for the entire system.

According to program documentation, the CBTT program spent an average of deploy the first 6 miles of the persistent system. CBP estimated the cost of the first two procured mobile toolkits to be $1.5 million total. . Once one vendor is selected, a single per mile to procure and , and the 24 CBP will also require funding to conduct tunnel adjudication. Adjudication is CBP’s process for investigating and confirming the presence of illicit cross-border tunnels.

This process uses the mobile toolkit technologies and confirm the existence of an illicit tunnel is performed to . average adjudication operation operations occur . costs . According to acquisition documentation, the and the average adjudication operation . These An added cost during tunnel adjudications is the currently relies on. However, the CBTT program is procuring a adjudication via , if a tunnel is found.

The are estimated to cost $726,000. Once the transport to along the vast Southwest border. is procured, Border Patrol will need to fund its Border Patrol in FY 2024 for In addition to assisting with adjudication, the tunnels. Remediation operations occur when a tunnel is discovered during and can involve Border Patrol filling tunnel cavities with concrete to prevent use. Remediation follows a successful adjudication, which the program estimates happens roughly twice a year.

The average remediation operation costs approximately will also help CBP remediate discovered , which includes costs for 22 According to Program Management Office documentation as of February 2024. 23 Joint Explanatory Statement Accompanying H.R. 2882, Further Consolidated Appropriations Act, 2024, Div. C, Department of Homeland Security Appropriations Act, 2024, Pub.

L. No. 118-47.

24 The average cost per mile for procurement and deployment was determined using the sunk cost data from the original 6 miles of the persistent systems. www.oig.dhs.gov 7 OIG-25-33 FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE OFFICE OF INSPECTOR GENERAL U.S. Department of Homeland Security physically securing illicit cross-border tunnels to render them unusable. The CBTT program estimated it would cost an additional remediation for each mission operation. per person to travel during adjudication and Program documents indicated the need for CBP to account for the costs of procuring and refreshing the persistent and the mobile systems. From FY 2024 through FY 2029, persistent systems will be procured annually. A technical refresh that includes updating and upgrading software will occur at the persistent system’s of the original procurement costs.

The toolkits will require a refresh after roughly 50 percent of procurement costs. , costing of , at an estimated 10 percent Additional Staff Will Be Needed as More Technology Is Deployed Personnel costs are expected to rise as the program expands, just as technology costs will 25 increase. For example, the CBTT program must hire a contracting officer’s representative once a vendor contract is awarded. At the time of our audit, members of the CBTT team took on the collateral duties of the contracting officer’s representative, as well as the duties of a deputy 26 According to program program manager and project manager, due to position vacancies. documentation, taking on the collateral duties of these critical roles can lead to burnout and single points of failure, so it is important the program hire additional staff as it progresses. Operations Directorate, NSO will also require more staff27 to provide support as more technologies are deployed.

By June 2025, the CBTT program plans to move the TRC to the Subterranean Operations Center within Border Patrol’s Headquarters Intelligence Division.28 NSO expects it will need and to staffing model where In preparation for future staffing needs, NSO developed a hybrid Border Patrol intends to operate the persistent system 24/7, with preventive and corrective maintenance occurring as needed. When the persistent system capability is at Full Operational , TRC operators will Capability, or deployment of 25 General Services Acquisition Manual, Section 501.604. The contracting officer’s representative’s role is to develop proper requirements and ensure the contractors meet the commitments of their contracts, such as the timeliness and delivery of quality goods and services, as required by the contract. 26 As of May 2024, the CBTT program had .

27 During our survey work, NSO was composed of was . . , and the Tunnel Reachback Center 28 NSO is part of the Headquarters Intelligence Division within the Operations Directorate. www.oig.dhs.gov 8 OIG-25-33 FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE OFFICE OF INSPECTOR GENERAL U.S. Department of Homeland Security analysis of the persistent systems was , to keep up with data analysis. During our audit work, we learned data . analyze its data. Agents reported it could Border Patrol agents were trained to monitor the persistent system and officials, this . One Border Patrol agent we met with said he .

According to program . Additionally, Border Patrol agents analyzing the data were not . Instead, the agents we spoke with worked in intelligence positions. As more technology is deployed, the TRC’s planned expansion under NSO may help ensure that the CBTT program has enough staff with sufficient expertise to best use the collected data.

Effective Coordination Will Be Needed as the Program Progresses Program officials, local Border Patrol agents in the field, and analysts and operators at the TRC must coordinate to effectively mission and meet strategic plan objectives. The systems to carry out the CBTT program . For example, once the TRC expands, Patrol agents will have access to vital resources, . Local Border Once a tunnel’s location is confirmed, a program official can plan for remediation, award and execute a remediation contract, and archive all contract deliverables to ensure historical documentation is preserved and accessible.

Therefore, the CBTT program and its partners will need to coordinate effectively to achieve CBP’s strategic plan goals. CBP has made progress in identifying tunnel detection technologies since our 2021 audit. Such technology is critical to protect our nation’s borders by providing Border Patrol and its partners with capabilities needed to identify, assess, breach, and remediate cross-border tunnels. In addition, adequate resources and effective coordination will be needed to fully implement CBP’s strategic plan.

Management Comments and OIG Analysis CBP declined to submit management comments. www.oig.dhs.gov 9 OIG-25-33 FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE OFFICE OF INSPECTOR GENERAL U.S. Department of Homeland Security Appendix A: Objective, Scope, and Methodology The Department of Homeland Security Office of Inspector General was established by the Homeland Security Act of 2002 (Pub. L. No. 107−296) by amendment to the Inspector General Act of 1978. We conducted this audit to determine whether CBP’s CBTT program has the technology to identify, assess, breach, and remediate cross-border tunnels. We researched and applied Federal, departmental, and component criteria related to CBP’s mission, responsibilities, and technology.

We obtained and analyzed reports, testimony, and other documents pertaining to the CBTT program technology. Additionally, we reviewed Government Accountability Office and DHS OIG reports to identify relevant findings and recommendations and associated follow-up actions. During this audit, we obtained over 70 documents and conducted 10 interviews with program and technology officials and staff. We conducted virtual interviews with CBP’s Program Management Office Directorate’s CBTT program and the Operations Directorate’s, NSO Office.

We interviewed a supervisory Border Patrol agent assigned to the Southwest border who analyzed persistent system data. We also met with the DHS Office of Program Accountability and Risk Management and the DHS Science and Technology Directorate. We conducted one site visit to the Southwest border during March 2024. The site visit included meetings with CBTT program subject matter experts and a physical scientist from CBP’s Laboratories and Scientific Services.

Additionally, we interviewed both supervisory and non- supervisory Border Patrol agents in the sector who analyzed persistent system data and received a data analysis demonstration on the sector’s persistent system. We received a tour of a persistent system installation and a live, hands-on demonstration of the mobile toolkit at the program’s testing site. Following the mobile toolkit demonstration, we observed live data processing for the mobile technologies back at the sector. In addition, we visited a proposed persistent system deployment location.

We assessed internal controls related to our audit objective. Specifically, we assessed the design, implementation, and effectiveness of controls in relation to our audit objective. Certain control weaknesses are discussed in the body of this report. However, because our assessment was limited to these internal control components and underlying principles, it may not have disclosed all deficiencies that may have existed at the time of this audit. www.oig.dhs.gov 10 OIG-25-33 FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE OFFICE OF INSPECTOR GENERAL U.S. Department of Homeland Security We conducted this audit from February 2024 through April 2024 pursuant to the Inspector General Act of 1978, 5 U.S.C. §§ 401–424, and according to generally accepted government auditing standards.

Those standards require that we plan and perform the audit to obtain sufficient, appropriate evidence to provide a reasonable basis for our findings and conclusions based on our audit objectives. We believe that the evidence obtained provides a reasonable basis for our findings and conclusions based on our audit objectives. DHS OIG’s Access to DHS Information During this audit, CBP provided timely responses to our requests for information and did not delay or deny access to information we requested. www.oig.dhs.gov 11 OIG-25-33 FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE OFFICE OF INSPECTOR GENERAL U.S. Department of Homeland Security Appendix B: Report Distribution Department of Homeland Security Secretary Deputy Secretary Chief of Staff Deputy Chiefs of Staff General Counsel Executive Secretary Director, GAO/OIG Liaison Office Under Secretary, Office of Strategy, Policy, and Plans Assistant Secretary for Office of Public Affairs Assistant Secretary for Office of Legislative Affairs Commissioner, CBP Audit Liaison, CBP Audit Liaison, USBP Office of Management and Budget Chief, Homeland Security Branch DHS OIG Budget Examiner Congress Congressional Oversight and Appropriations Committees www.oig.dhs.gov 12 OIG-25-33 FOR OFFICIAL USE ONLY//LAW ENFORCEMENT SENSITIVE To view this and any other DHS OIG reports, Please visit our website: www.oig.dhs.gov Additional Information For further information or questions, please contact the DHS OIG Office of Public Affairs via email: [email protected] DHS OIG Hotline To report fraud, waste, abuse, or criminal misconduct involving U.S. Department of Homeland Security programs, personnel, and funds, please visit: www.oig.dhs.gov/hotline If you cannot access our website, please contact the hotline by phone or mail: Call: 1-800-323-8603 U.S. Mail: Department of Homeland Security Office of Inspector General, Mail Stop 0305 Attention: Hotline 245 Murray Drive SW Washington, DC 20528-0305