Who is Victor Romero from Heaven's Prisoners and what is their importance?

Victor Romero is of vague Hispanic origin and is described as a strong but wiry man, of thin build, with light skin and many curly ringlets of black hair which he wears oiled. Romero served in Viet Nam as a sniper and at one point brags of a prolonged field operation during which he collected human ears as grisly kill trophies. Dave verifies at least that aspect of Romero's story by examining the wizened ears after killing Romero. Romero's intelligent behavior throughout the novel indicates he is a dangerous man capable of inflicting enormous wrongs upon any who cross his path.