Speculation is swirling over who may be picked as the special master to review confidential records seized from former President Donald Trump’s Mar-a-Largo estate.

Legal experts say the potential pool of candidates is small, noting the person would have to be able to hold or qualify for a security clearance, given the sensitive nature of some of the documents, some of which reportedly involve another nation’s nuclear capabilities. The U.S. Department of Justice also would likely want a suitable candidate to help insulate it from claims the investigation is politically biased.