There was years ago an out of the blue vow by Judge Roberts to pursue sex crimes involving children. Why is this guy now quiet?
However, maybe President Trump could push for a grandfather clause in older adoption cases and get Judge Roberts off his self-inflicted hook. And free him up to be a conservative judge? If he was one?
A presidential pardon would only get Roberts off the hook in the USA. It would however bring an international public spotlight to the effect that the highest USA court official had a demonstrable need to be pardoned for underage human trafficking, which probably does not make the USA or the USSC or President Trump or Roberts look very good to anyone. It also would serve to tip off Irish authorities that Roberts is likely to have been guilty of illegal adoption and human trafficking under Irish law, and therefore could well trigger an indictment in Ireland and a request by Ireland to the USA for extradition of Roberts to Ireland for prosecution in Irish jurisdiction. That would all be rather messy IMHO and have a serious long term effect on Irish-American diplomatic relations...
(see also: Ex Parte Grossman, 267 U.S. 87 (1925) for a definition of “offenses against the United States”)