In regards to whether simply leaving the jurisdiction is grounds for tolling the statute of limitations, see 18 USC 3290, which is a one-sentence law reading:

In regards to whether simply leaving the jurisdiction is grounds for tolling the statute of limitations, see 18 USC 3290, which is a one-sentence law reading: No statute of limitations shall extend to any person fleeing from justice It can be reasonably argued that leaving the country after having committed the offense is fleeing from justice. I'm not aware of any supreme court ruling on the matter though, and I am not a lawyer. Edit: Thanks for the link!