when questioned, castellon denied any involvement in the murders.loyment and motor vehicle records showed he recently moved to texas from colorado and bought a set of commander brand snow tires when he was there. these were similar to the impressions found at the crime scene. >> we saw a lot of uniformity between the tire impressions of the defendant's vehicle to the actual casts that we had taken from the crime scene. as far as tread design, tread size, the logo itself. >> investigators noticed the back window of castellon's car was broken. pieces of that window were compared to the glass found on the leg of one of the murder victims. the refractive index, a measure of the speed of light as it passes through the glass, was identical in both samples. finally, investigators compared castellon's fingerprints to the bloody print found on one victim's leg. it matched the middle finger on his right hand. >> it was a huge moment. it was the definitive moment in that we've got a very, very good case and let's get it to trial. we've got the right man, witho