in sanchez's trash, and in megan's own car. it was the only piece of evidence that tied sanchez to everything. investigators also searched sanchez's truck for blood. >> when the tech put a luminol on the inside of the vehicle, it lit up like a christmas tree. >> dna testing revealed blood on the passenger seat was megan's. >> there was a horizontal apparent blood stain right in the area where megan's wound was to her side, indicating that she had been sitting upright in the passenger seat of that truck at one point. so she wasn't dead. she was sitting. >> forensic tests on the scrape mark on the side of megan's car matched the paint from sanchez's truck. investigators test fired the ak-47 and compared the bullets to fragments found with megan's body. >> we tied that rifle to the crime scene and to the body both with the fragments that were taken from the car, from the crime scene. certainly, that helped to tie the rifle in to mr. sanchez and mr. sanchez then to the crime scene. >> then police discovered that sanchez's real target that night