detective jose trevino worked in the auto industry before going into law enforcement. he was particularly interested in the passenger side mirror with a built-in heating element found near rafael's body. >> i recognized it as a chrysler emblem, so therefore, it led me to believe it was a chrysler vehicle. >> by checking the part number, investigators learned that the mirror came from a dodge ram pickup truck manufactured between 1999 and 2002. >> to most people outside the auto industry, those numbers wouldn't mean much. to an engineer, these codes are much like identifications, such as your social security number or even dna. >> although this narrowed the search considerably, these trucks were extremely popular. >> seemed like a needle in a haystack, because now it's a dodge pickup truck, very commonly used in texas. it narrows it down to have the year range, but still, there's so many. and i thought maybe it was impossible to find it. >> but investigators could narrow it down further since they knew the dodge ram pickup truck was red. police used local media outlets