From the information you provided, your concerns should probably be more than the loss of your truck. It is likely CBP will send you a notice of seizure of your truck, but in the end, it is likely they will confiscate the truck. Your son may face criminal prosecution for bringing illegal aliens to the United States which is a felony. If he is convicted or found guilty of transporting illegal aliens in to US, he may either go to jail and or pay civil fines or both. Finally, unless he is a US citizen, DHS may seek to deport your sons from the US.
Answered on Jan 31st, 2013 at 11:50 PM