Many immigrants believe that if they accept the pre-trial intervention or diversion programs offered to criminal defendants after they are arrested, they will not face deportation from the United States. That is simply not true. To understand why, you must understand that there are two different laws that the U.S. Immigration and Customs Enforcement (ICE) use to deport people from the United States. One set of laws usually applies to people who entered the country without inspection, admission or parole. The other set of laws applies to lawful permanent residents (LPRs) and non-immigrants, including students, tourists, workers, etc.
For ICE to deport someone in the second group (LPRs, etc.) based upon certain crimes, there must be a conviction. A conviction includes anytime a criminal defendant enters a plea of guilty or no contest and is adjudicated guilty or the adjudication of guilt is withheld. A successfully completed pre-trial intervention or diversion program will result in the charges being dropped. If the charges are dropped there is no conviction and an LPR or other lawfully admitted non-immigrant cannot be deported from the U.S. based upon that crime.
HOWEVER, if that same LPR or non-immigrant successfully completes a pre-trial intervention or diversion program and the criminal charges are dropped, they can still face deportation in certain circumstances. If anyone in this second category leaves the U.S. and comes back, they are subjected to the same set of laws as someone who entered the U.S. without inspection, admission or parole.