It may help identify one of the men who killed a dairy worker on his first day on the job.
This is the one piece of evidence keeping a killer on the hook for a murder at a Madera County Dairy.
Images from the dairy's surveillance system show two armed suspects walking into the barn and opening fire on two workers.
The video is too graphic for TV, but the suspect wearing a unique sweatshirt killed 19-year-old Ivan Torres, shooting him twice... Once, execution-style.
John Anderson, Madera County Sheriff: "He wouldn't have had a chance. He probably just looked over and saw a guy pointing a rifle at him."
The sweatshirt stands out because of its colorful stripes. From left to right, it has a green sleeve, a white stripe down the middle, and a red sleeve - the same color pattern as the Mexican flag.
But investigators are struggling to find other clues.
The murder happened in the dark, just before midnight, so nobody in the remote farm area saw anything, and rain washed away any tire tracks or footprints leading away from the dairy.
Inside the barn, regular cleanings erased any trail investigators could've followed.
Anderson: "They're like a hospital. Between every milking, they sanitize it and all that. There's absolutely no physical evidence."
There's no apparent motive either.
Detectives ruled out robbery because the killers didn't take anything and murder would've been excessive.
Ernie LiCalsi, Madera County District Attorney: "If they were robbing them, they were already shot, there was no need to do this execution on the one victim."
They also ruled out a vendetta and mistaken identity.
The video doesn't provide much more evidence because the suspects disguised their identities.
But they left this one clue... A distinct red, white, and green trail investigators hope leads to an arrest.
Nobody at the dairy wanted to talk on camera today, but both workers and neighbors say the random nature of the incident is very scary.
Some say they stay away from the area at dark now.