(NewsNation) —  Police in South Florida are asking the public to help solve a 50-year-old cold case.

The remains of a teenager who went missing nearly 50 years ago have been identified through advanced DNA technology, and detectives believe she may have been slain by a police officer who was also a serial killer.

Susan Poole, 15, was a high school dropout whose family reported her missing just before Christmas in 1972. She had been living between the family’s home in a trailer park near Fort Lauderdale and with a friend in a nearby apartment, Palm Beach County Sheriff’s Detective William Springer said during a news conference Thursday.

“Nobody knew where she went,” he said, noting that her clothes and pocketbook were left at the friend’s apartment.

A year and a half later, in June 1974, sheriff’s deputies were called to a remote location in Palm Beach County where human remains were found.

“She was tied up in the mangroves with wire to a tree,” Springer said. “She was skeletal remains, totally nothing left of her except bones.”

The location and evidence made police think Poole could be a victim of Gerard Schaefer, a former cop and sheriff deputy turned serial killer.

When Poole disappeared, Schafer was a local police officer. And just months earlier, a young girl reported “a narrow escape” after he offered her and her friends a ride to the beach.

In 1973, Schaefer was convicted of killing a 16-year-old named Georgia Jessup and 17-year old Susan Place.

When police searched Shaefer’s home, they reportedly found jewelry and items believed to be souvenirs from various, unknown victims.

Schaefer was killed in prison in 1995 while serving a life sentence. Investigators believe he could have killed dozens of other women in Florida and across the country, leaving a trail of remains that may never be found. 

“At this point, it all appears to be Gerard Schaefer,” Springer said during an appearance Monday night on “NewsNation Prime.”

“At the same time, you can’t rule out the possibility that somebody else could be involved,” Springer added.

Investigators are hoping to speak to several friends who lived near Poole when she disappeared and could possibly fill in some blanks about her activities during that time.

Springer wants to know if she frequently hitchhiked or whether she had ever confided in them about any kind of relationship with Schaeffer.

Springer told NewsNation’s Marni Hughes that he’s currently trying to locate four of Poole’s former friends named Greg Anderson, Keith Keiffer, Julie Hunt, and a Michelle Williamson.

“If I can talk to these people, and anybody else who may have known Susan in 1972, I can move forward with the investigation and give the family some closure.”

The Associated Press contributed to this report.