Depending on where you live, ICE may be surveilling your community for illegal immigrants.  Also, if your family member has no legal status in the U.S. and he or she has committed a crime (DUI, Driving without a License, Simple Assault, Theft, etc.) they may be flagged by ICE for review of their immigration status, when they are initially charged with a crime.  When ICE interviews you, remember that you are not obligated to speak with ICE.  Many times, aliens make statements which harm their chances for release. 

In most cases, if a person is arrested for a crime, and ICE determines they are illegal, then ICE will put a “detainer” or hold on them.  Therefore, even if the criminal bond is paid, or if the person is released with zero bond by a judge in criminal court, they will not be released, but will instead be transferred to an immigration detention center.

Typically jails have up to 72 hours to hold someone with such an ICE detainer. You should speak with an immigration attorney before paying criminal bail as there may be a detainer on you. 

In some cases, ICE moves aliens from criminal court to immigration custody even while their criminal case is pending.  In such a situation, the case can become very complicated and requires an attorney to make sure the alien does not miss any criminal court hearings, or if they are brought back to criminal court, they should likewise not miss any immigration court hearings.