Trump Special Counsel Plays Cards Close on What Makes a Witness

The special counsel’s election conspiracy investigation of Donald Trump highlights longstanding tension about whether prosecutors can assure prospective cooperators they’re purely witnesses or stick to calling them “subjects,” who have potential exposure.

Three defense lawyers representing people sought for voluntary interviews say they’re frustrated that special counsel Jack Smith’s team insists on labeling their clients subjects without providing additional detail as to where they fit in the case or whether they could become a target. They’ve asked to remain anonymous to discuss sensitive matters.

Justice Department guidance doesn’t define what a witness is and prosecutors prefer the flexibility of the ...