There are two possible ways Brett Kavanaugh might be indicted:
a) A federal perjury charge has been suggested by some Senators.
That has been extended recently to some of BK's testimony around his drinking habits and allegations of sexual assault and witness to sexual assault.
b) There are some allegations that Maryland may not have a statute of limitations with respect to sex crimes.
I think a Brett Kavanaugh indictment dated the next 4 years claim might be interesting.