DHS uses prosecutorial discretion in deciding to what extent it will enforce immigration laws, including whether to place aliens in or take them out of the removal process. However, the Department does not collect and analyze data on the use of prosecutorial discretion to fully assess its current immigration enforcement activities and to develop future policy. Although the Office of Policy is responsible for developing department-wide policies and programs, DHS has not required this office to gather or use data to assess the effect of prosecutorial discretion on immigration enforcement activities. The Department also does not have a mechanism to continuously monitor its use of prosecutorial discretion and improve future policy. As a result, DHS may not be using its significant investment in immigration enforcement as efficiently as possible. The Department may also be missing opportunities to strengthen its ability to remove aliens who pose a threat to national security and public safety.