The lawyers working with the FBI from the DOJ are career employees. They are not appointed. Lynch has stated that several times.
Looking at a job posting list for a DOJ office in California, these jobs have terms, terms are appointed. It’s not like the civil service which is based on merit. That isn’t to say there probably isn’t a strong merit based component, they do want to win their cases after all, but an appointment is political. To top that off, the DOJ is part of the executive branch.
Something about this brings to mind what happens every time there is a new crew member in the landing party on Star Trek.