From Fierce Homeland Security:

The components of the Homeland Security Department have worked to collaborate despite their misaligned field office structures, but the department leadership has neglected to help, the Government Accountability Office says. Each component brought its own field structure and geographic regions to DHS, complicating situations where they need to collaborate. For instance, a single Customs and Border Protection field office may have to work with multiple Immigration and Customs Enforcement field offices to investigate a criminal organization within the bounds of one CBP office that spans more than one of ICE’s.