May 8, 2005 — Brazilians, Central Americans and others are expected to overtake Mexican nationals as the largest group of undocumented immigrants entering the Rio Grande Valley. Although some federal authorities said the demographic shift has already happened, figures given to The Brownsville Herald this month show the number of OTM (Other Than Mexicans) immigrants detained in Deep South Texas has exploded in the last two years but remains slightly behind the number of Mexican nationals.