It is not just DACA cases that are transferred to field offices; all sorts of application, including Adjustment of Status or AOS (application to receive a green card or permanent residency) and naturalization, are typically sent to local offices. The reasons are many:
- USCIS made a mistake or you made a mistake and the application has now been sent to the right place.
- Personnel changes within USCIS prompting transfer of work to wherever it can be done faster.
- Redistribution of work between different offices when some offices get more workload while other offices have less work.
- The applicant files form AR-11 for change of address and that necessitates moving the case.
- Something popped up during the decision making process that requires the case to be handled locally. Since local offices are much closer to the applicant's residence and/or employment and the agency has better relationship with the local law enforcement and businesses, it is much easier for the field office to handle such matters. It is not unusual for USCIS to make phone calls to police, employers, landlords, school/university, churches, etc. to conduct their investigation as part of background check. In rare cases, even a visit by a USCIS officer may be made to a police office or employer.
- While DACA cases are being handled without personal interviews, in other immigration petitions, it is generally a sign that the applicant will be directed to appear in person and provide original documentation in support of the case.