The detectives are also using other items like jewelry and clothes, but it all still provides an incomplete portrait of a murder victim.
On a stretch of road in the Angeles National Forest, beyond a yellow guard rail is a patch of dirt where more than 15 years ago a young woman's body was set on fire and left to burn like a pile of trash.
"The fire was actually an attempt to hide the victim's identity," said Los Angeles Police Detective Mitzi Roberts.
Roberts works on the LAPD's Cold Case Unit. And she's talking about a woman known only as "Jane Doe," a woman probably 18 to 22 years old, who was strangled in August 1994.
"Some passersby observed what appeared to be burning trash off the side of the freeway, and they stopped to take a look at it, kicked some dirt on it, and realized that it was actually a body that was burning," said Roberts.
Because of the fire, authorities weren't able to identify the victim at the time of the murder, and to this day, her identity remains a mystery.
"Memories fade and things like that, so we're at a severe loss because of the loss of time and how long it's been," said Roberts.
But at the very least, Roberts is hoping to learn who this woman was. And she's working with the very little evidence that was recovered at the crime scene.
Specifically, gold rings and a gold chain. The jewelry made it through the fire set by the killer. There's also a medallion of Jesus Christ.
And then there's what was left of the woman's dress, with a floral print. They help provide an incomplete portrait of a murder victim.
"I have to believe that somewhere out there there's a family member, a mother, a father, grandfather, grandmother, sibling that's missing this child," said Roberts.
The Cold Case Unit is also trying to reconstruct how the victim looked, so they turned to Marilyn Droz, a forensic artist with more than 30 years' experience.
"My impression, from the pictures that I had to work with, was that she was a young Latina woman, an attractive girl," said Droz. "What was significant that I wanted to bring out in the picture, was the gap between her two front teeth and some small moles on her forehead."
It's likely the young victim was Hispanic or Filipina, and probably Catholic.
Roberts is hoping some of these details will trigger something in someone's memory. Otherwise, this cold case may never be closed.
"This family probably is hoping that she's still missing, not dead, but hopefully or maybe the family just needs closure, and I would just have to tell them the truth and offer to bring that healing process somehow," said Roberts.
If you have information related to this case, you are asked to call the Los Angeles Police Department at (877) 527-3247 (LAPD-24-7).