[quote=ucodegen]But there may be an issue w/ having to file a flight plan.[/quote]
A flight plan is not required for VFR flight. (And even if it was, he could just not file one and nobody would ever know.)
Authorities are now speculating that he might’ve fled to Mexico. What better way to get there unnoticed than in a Cessna? The DEA and ICE monitor northbound flights very closely. I’m not sure how closely they monitor southbound ones, but a clever operator could make it work.