@w7voa Doesn't a US Presidential pardon nullify their Fifth Amendment rights against self-incrimination? If so, shouldn't it be open season for prosecutors to question them about their co-conspirators and then charge them with perjury if they fail to testify?
Kastigar v. United States, 406 U.S. 441 (1972)
United States v. Wong, 431 U.S. 174 (1977)