In December 2012, we reported on Border Patrol’s evolving approach for deploying agents along the southwest border. In that report we found that Border Patrol’s 2004 Strategy provided for increasing resources and deploying these resources using an approach that provided for several layers of Border Patrol agents at the immediate border and in other areas 100 miles or more away from the border (referred to as defense in depth). According to the CBP officials we interviewed for our report, as resources increased, Border Patrol sought to move enforcement closer to the border over time to better position the agency to ensure the arrest of those trying to enter the country illegally. Additionally, headquarters and field officials said station supervisors determined (1) whether to deploy agents in border zones or interior zones, and (2) the types of enforcement or nonenforcement activities agents were to perform. Similarly, Border Patrol officials from the five sectors we visited stated that they used similar factors in making deployment decisions, such as intelligence showing the presence of threat across locations, the nature of the threat, and environmental factors including terrain and weather. We reported in December 2012 on Border Patrol data from fiscal year 2011 that showed how agent workdays were scheduled and found differences across sectors in the percentage of agent workdays scheduled for border zones and interior zones and across enforcement and nonenforcement activities. Specifically, we found that while Tucson sector scheduled 43 percent of agent workdays to border zones in fiscal year 2011, agent workdays scheduled for border zones by other southwest border sectors ranged from 26 percent in the Yuma sector to 53 percent in the El Centro sector. Our analysis of agents deployed for enforcement compared to nonenforcement activities ranged from 66 percent for Yuma sector to 81 percent in Big Bend sector. Border Patrol officials we interviewed attributed the variation in scheduling border zone deployment in fiscal year 2011 to differences in geographical factors among the southwest border sectors—such as varying topography, ingress and egress routes, and land access issues, and structural factors such as technology and infrastructure deployments— and stated that these factors affect how sectors operate and may preclude closer deployment to the border. Additionally, we found that many southwest border sectors have interior stations that are responsible for operations at some distance from the border, such as at interior checkpoints generally located 25 miles or more from the border, which could have affected their percentage of agent workdays scheduled for border zones. We have planned work to assess Border Patrol deployment and management of agents across the southwest border beginning later this year. We also reported in December 2012 that Border Patrol sector management used changes in various data over time to help inform assessment of its efforts to secure the border against the threats of illegal migration, smuggling of drugs and other contraband, and terrorism. These data showed changes in the (1) percentage of estimated known illegal entrants who are apprehended, (2) number of seizures of drugs and other contraband, and (3) number of apprehensions of persons from countries at an increased risk of sponsoring terrorism. In addition, apprehension and seizure data could be analyzed in terms of where they occurred relative to distance from the border as an indicator of progress in Border Patrol enforcement efforts. Border Patrol officials at sectors we visited, and our review of fiscal years 2010 and 2012 sector operational assessments, indicated that sectors historically used these types of data to inform tactical deployment of personnel and technology to address cross-border threats. Our analysis showed that in most southwest border sectors less than half of Border Patrol’s apprehensions and seizures were made within five miles of the border in fiscal year 2011. In Tucson sector, for example, 47 percent of Border Patrol’s apprehensions of illegal entrants, 38 percent of the drugs and contraband seizures, and 8 percent of the apprehensions of aliens from special interest countries were within five miles of the border. However, our analysis also showed that Border Patrol had moved overall enforcement efforts closer to the border since the prior fiscal year. Further, we reported that Border Patrol sectors and stations tracked changes in their overall effectiveness as a tool to determine if the appropriate mix and placement of personnel and assets were being deployed and used effectively and efficiently, according to officials from Border Patrol headquarters. Border Patrol calculated an overall effectiveness rate using a formula in which it added the number of apprehensions and “turn backs” in a specific sector and divided this total by the total estimated known illegal entries—determined by adding the number of apprehensions, turn backs, and “got aways” for the sector. Border Patrol views its border security efforts as increasing in effectiveness if the number of turn backs as a percentage of estimated known illegal entries has increased and the number of got aways as a percentage of estimated known illegal entries has decreased. In our December 2012 report, we analyzed apprehension, turn back, and got away data from fiscal years 2006 through 2011 for the Tucson sector and found that while apprehensions remained fairly constant at about 60 percent of estimated known illegal entries, the percentage of reported turn backs increased from about 5 percent to about 23 percent, while the percentage of reported got aways decreased from about 33 percent to about 13 percent. As a result of these changes in the mix of turn backs and got aways, our analysis of Border Patrol data using Border Patrol methodology for our report showed that the enforcement effort, or the overall effectiveness rate for Tucson sector, improved 20 percentage points from fiscal year 2006 to fiscal year 2011, from 67 percent to 87 percent. Border Patrol data showed that the effectiveness rate for eight of the nine sectors on the southwest border also improved from fiscal years 2006 through 2011, using Border Patrol methodology. At the time of our review in 2012, Border Patrol headquarters officials said that differences in how sectors defined, collected, and reported turn back and got away data used to calculate the overall effectiveness rate precluded comparing performance results across sectors. They stated that each Border Patrol sector decided how it would collect and report turn back and got away data, and as a result, practices for collecting and reporting the data varied across sectors and stations based on differences in agent experience and judgment, resources, and terrain. The ability to obtain accurate or consistent data using these identification sources depends on various factors, such as terrain and weather, according to Border Patrol officials. As a result of these data limitations, Border Patrol headquarters officials said that while they considered turn back and got away data sufficiently reliable to assess each sector’s progress toward border security and to inform sector decisions regarding resource deployment, they did not consider the data sufficiently reliable to compare—or externally report—results across sectors at the time we issued our report in December 2012. Border Patrol headquarters officials issued guidance in September 2012 to provide a more consistent, standardized approach for the collection and reporting of turn back and got away data by Border Patrol sectors. As we reported in 2012, Border Patrol officials expected that once the guidance was implemented, data reliability would improve. Since that time, DHS has reported the effectiveness rate in its Fiscal Year 2015- 2017 Annual Performance Report as a performance measure and method to publicly report results of its border security efforts on the southwest border. In March 2014 and April 2015, we reported that CBP had made progress in deploying programs under the Arizona Border Surveillance Technology Plan, but that CBP could take additional action to strengthen its management of the Plan and its various programs. The Plan’s acquisition programs include fixed and mobile surveillance systems, agent portable devices, and ground sensors. Specifically, we reported in March 2014 that CBP had identified the mission benefits of its surveillance technologies, as we recommended in November 2011. CBP had identified mission benefits of surveillance technologies to be deployed under the Plan, such as improved situational awareness and agent safety. However, we also reported that the agency had not developed key attributes for performance metrics for all surveillance technology to be deployed as part of the Plan, as we recommended in November 2011. As of May 2015, CBP had identified a set of potential key attributes for performance metrics for all technologies to be deployed under the Plan; however, CBP officials stated that this set of measures was under review as the agency continued to refine the measures to better inform the nature of the contributions and impacts of surveillance technology on its border security mission. While CBP had yet to apply these measures, CBP had established a time line for developing performance measures for each technology. In November 2014, CBP officials stated that baselines for each performance measure were to be developed, at which time the agency was to begin using the data to evaluate the individual and collective contributions of specific technology assets deployed under the Plan. Moreover, CBP plans to establish a tool by the end of fiscal year 2016 that explains the qualitative and quantitative impacts of technology and tactical infrastructure on situational awareness in specific areas of the border environment. While these are positive steps, until CBP completes its efforts to address our recommendation and fully develop and apply key attributes for performance metrics for all technologies to be deployed under the Plan, it will not be able to fully assess its progress in implementing the Plan and determine when mission benefits have been fully realized. Further, in March 2014, we found that CBP did not capture complete data on the contributions of these technologies, which in combination with other relevant performance metrics or indicators could be used to better determine the contributions of CBP’s surveillance technologies and inform resource allocation decisions. Although CBP had a field within its Enforcement Integrated Database for data on whether technological assets, such as SBInet surveillance towers, and nontechnological assets, such as canine teams, assisted or contributed to the apprehension of illegal entrants and seizure of drugs and other contraband, according to CBP officials, Border Patrol agents were not required to record these data. This limited CBP’s ability to collect, track, and analyze available data on asset assists to help monitor the contribution of surveillance technologies, including its SBInet system, to Border Patrol apprehensions and seizures and inform resource allocation decisions.