El Paso police say they were able to connect Valtierra to the first three crimes due to his DNA profile being linked to DNA found at those crime scenes.
"The probability of selecting an unrelated person at random who could be the source of this DNA profile is approximately 1 in 21.89 sextillion for caucasians, 1 in 164.4 septillion for blacks, and 1 in 338.8 quintillion for Hispanics," according to the affidavit.
The second victim also provided information about characteristics of Valtierra's penis that were verified when he was arrested and a body search warrant was executed.
A man named Arturo Valtierra-Payan with the same birth date as the man arrested in El Paso was arrested in Chihuahua in 2009 for carrying an unlicensed weapon, and served two years in Cereso Prison in Chihuahua.
A couple of years before that Valtierra was caught by the Border Patrol twice in 2007 after illegally entering the U.S. and was deported back to Mexico.