Rifaat Assad, who led the killings of 40k people in Hama and brother of Hafez, fled to Beirut and traveled from there.
This is becoming a serious problem and is probably going to put us with future issues with the new administration in Syria. I imagine they are not currently happy when we let the war criminals who killed them pass through our country with ease.
Bear in mind this guy has like 10 European warrants for war crimes.