(written from a Production point of view)
Marco Sanchez (born 9 January 1970; age 45) is the actor who played Corporal M. Romero in the Star Trek: Enterprise episode "The Xindi". Due to costume reuse, two other actors wore uniforms with the name tag "M. Romero" but with different ranks. Sanchez will also appear in the upcoming Star Trek Into Darkness. 
He is most notable as playing Sensor Chief Miguel Ortiz for two seasons on the science fiction television series seaQuest DSV. Co-stars Stephanie Beacham and Rosalind Ingledew had previously guest starred in TNG: "Ship in a Bottle" and "The Outrageous Okona", respectively.
Sanchez is one of two MACO's to appear on Desperate Housewives, the other, of course, being Steven Culp, who played Major Hayes. Sanchez also played Carlos Sandoval on the television series Walker, Texas Ranger from 1997 until 1999. Upon leaving the show, he had a role in the spin-off Sons of Thunder. Most recently he played Alejandro Rivera on 5 episodes of NCIS.