Who is "Valentine Jane Doe?" Police in Florida found the body of a young woman in a popular camping area on Valentine's Day 1991.

Composite sketches may finally help reveal the identity of this victim.

For one young woman a visit to the tropical paradise of the Florida Keys in 1991 would be her last.

She's known only as "Valentine Jane Doe" because she was murdered on Valentine's Day 25 years ago.

Investigators estimate her age as between 16 and 25 years old.

"You wake up in the middle of the night and you're like, Did we look at this? Who is she?" said Monroe County Sheriff's Detective Manuel Cuervo. "Is there anything that we missed in looking at the evidence, at the clues that we have for her?"

U.S. 1 is the only coastal highway connecting the Florida Keys to Miami. Investigators say Valentine Jane Doe was headed north and had hitchhiked about 31 miles before she met a brutally violent end.

"She was sexually assaulted," said Cuervo. "She was stripped, she was completely nude when she was found bludgeoned and strangled."

She was found on February 14, 1991, in an overgrown ravine off the highway by windsurfers.

Police say she was strangled with the strings of her bikini top. Her body was brutally beaten. She had been left for dead, face-down in the water.

"There was evidence she did fight," said Cuervo.

When cops arrived on scene, the first thing they saw were drag marks in the dirt. The path led investigators straight to the young woman's body.

"The evidence is clear that she was most likely forced here, obviously," said Cuervo.

After finding Valentine Jane Doe's body in the area, investigators say over the years they've received nearly 600 leads.

Why was Valentine Jane Doe hitchhiking along the highway?

Scattered near the body, more clues: clothes she wore when she was attacked. A red-and-blue-striped sweater with a label that read "Forenza"; cut-off jean shorts; black moccasin booties.

Her skin was fair, and most interesting to detectives, she didn't have tan lines.

"We believe that she is from a northern territory, due to the fact that she did not have any tan lines," said Cuervo. "You know, usually you come to the Florida Keys, you're going to have a tan line if you're here for any amount of time."

"She was found on Valentine's Day, and strangely enough she has a tattoo on her shoulder that says 'love' inside of a heart," said Cuervo.

Investigators say, she had multiple piercings in one of her ears, and her teeth were perfect.

"Her teeth were pristine. Her teeth were very good. Very straight. Like she was well-cared for," said Cuervo.

And, what could be the most important clue, Valentine Jane Doe may have been a mother.

"She carried a child full-term is what the medical examiner is indicating," said Cuervo. "So there has to be someone out there that perhaps has her DNA that could help us identify her."

If she was a mother, what happened to Valentine Jane Doe's baby? That child would now be at least 25 years old.

"Somebody deserves a name. Somebody deserves justice," said Mike Murphy, program manager for the Long-Term Missing at the National Center for Missing and Exploited Children in Alexandria, Virginia. "We all do and we have an opportunity to make that happen."

For now, Valentine Jane Doe is in the county social services vault. Her body is marked "unidentified."

"We want to bring her remains home to someone who really cares and loves her," said Cuervo.

And as the 25th anniversary of Valentine Jane Doe's murder approaches, to date there have only been five suspects in the case, none of them charged.

Still, detectives say they will never stop searching for the identity of the young woman with the heart tattoo.

"Some will think that time is our enemy," said Murphy. "I will tell you time is on our side because we continue to look. We never stop looking."

If you have any information that could help in solving the mystery of Valentine Jane Doe, submit a tip to Crime Watch Daily.