What is illegal re-entry?
The act of illegal re-entry involves returning to the United States without prior approval from the Government (that's the Secretary of State) after that person has been excluded, deported, or removed as well as when admission has been denied.
Title 8 U.S. Code § 1326 states that is illegal for any person who “has been denied admission, excluded, deported, or removed or has departed the United States while an order of exclusion, deportation, or removal is outstanding” to enter, attempt to enter, or at any time be found in the United States.
Illegal re-entry is therefore considered a Federal crime and a felony ― which means that the services of a Federal criminal defense lawyer who has handled this particular immigration issue is important to a successful outcome.
And for many clients a successful outcome is a quick return to their home country, without having to spend a significant amount of time at the Federal Detention Center. It's entirely possible to arrange for a "time served" sentence and self-removal.