There are a number of ways in which a noncitizen may come in contact with immigration authorities (e.g., upon entering the United States, applying for a visa or other immigration benefit, or while incarcerated). 

 

Knowing how a noncitizen client may come in contact with the DHS may be important in determining whether and when a noncitizen client may be subjected to removal proceedings.  Because it is usually the case that the noncitizen is the one who makes the first contact, counsel may be able to advise a client on how to avoid such contact.

 

                When and how noncitizens come in contact with the immigration authorities may also determine their immigration status, whether they are inadmissible or deportable, whether they must be detained or can be released on bond, the types of relief available to them, and whether the DHS may be willing to exercise prosecutorial discretion not to remove them even though they are removable.

BIA

REMOVAL PROCEEDINGS " EVIDENCE " MIRANDA WARNINGS
Matter of ERMF & ASM, 25 I&N Dec. 580 (BIA 2011) (until a Notice to Appear is filed with the immigration court, immigration officers are not required, 8 C.F.R. 287.3(c), to advise the noncitizen that she has a right to counsel or that any statements made during interrogation can subsequently be used against her). http://www.justice.gov/eoir/vll/intdec/vol25/3725.pdf

Ninth Circuit

OVERVIEW - CONTACT WITH IMMIGRATION AUTHORITIES
Samayoa-Martinez v. Holder, 558 F.3d 897 (9th Cir. 2009) (DHS is not required to give warnings under 8 C.F.R. 287.3 until after an NTA is served on the noncitizen; statements taken before service of the NTA may be used against the noncitizen even in the absence of these warnings).

Other

OVERVIEW - CONTACT WITH IMMIGRATION AUTHORITIES
Article on motions to suppress in immigration proceedings: Stella Burch Elias, "Good Reason to Believe": Widespread Constitutional Violations in the Course of Immigration Enforcement and the Case for Revisiting Lopez-Mendoza. http://hosted.law.wisc.edu/lawreview/issues/2008_6/2_-_elias.pdf

The article concludes: "Applying the principles of Lopez-Mendoza, in light of the many changes of the previous twenty-five yearsmost notably the widespread violations of immigration respondents constitutional rights, the breakdown of the distinction between civil immigration and criminal proceedings, the decreased efficacy of ICEs internal regulations, and the diminishing availability of declaratory relief for noncitizensit is now time to revisit the holding of Lopez-Mendoza and reintroduce the exclusionary rule in immigration proceedings." Thanks to Dan Kesselbrenner