I received a letter from ICE telling me to report to their office so I can be deported. What will happen if I ignore this letter and do not show up?
If you ignore a "Bag and Baggage" letter from Immigration and Customs Enforcement (ICE), then this agency will refer your file to the fugitive unit. This is the ICE police force that tracks people down and arrests them.
ICE agents could arrest you at your home, place of work, or school, at any time. In fact, they often come at night, expecting the fugitive to be asleep in bed. If you are arrested, you will be kept in custody (detained) until travel arrangements can be made.
When and whether ICE agents come to arrest you depends on many factors, including the enforcement priorities of the local unit and its level of manpower.
Once you are listed as a fugitive, however, this information may also reach local law enforcement -- that is, regular police and so forth. If you are stopped for any offense (even speeding), you may be arrested and held for ICE.
Attempting to dodge removal by ignoring the "Bag and Baggage" letter may buy someone a bit more time in the United States as a fugitive, however there are other serious consequences. You could end up spending more time in jail or prison awaiting removal. You could be charged criminally. It is possible that friends or family could be charged with harboring a fugitive. The arrest could be embarrassing, frightening, or dangerous — in public, in front of your family, in your bathrobe.
Ignoring the Order of Removal could also count against you in any future attempt to come back to the United States.