The FBI and other agencies returned last week to a northeastern Ohio area where the bodies of two teenage girls were found in 1994.

The investigators used advanced technology to search the sites near the Berlin Lake Wildlife Area where Kathryn Menendez, 17, and Sarah Rae Boehm, 14, were found murdered, Fox 8 reports.

The FBI’s Evidence Response Team was joined by investigators from Portage County, Ohio, and Beaver County, Pennsylvania, during Friday’s search for evidence that may have been missed when the bodies were discovered.

“We'll take a parameter around the areas where we found both of the ladies' bodies and expand from that area,” FBI Special Agent Donna Camberio told the station. “ERT has the resources for sophisticated techniques we can use in searches, especially since so many years have passed since the actual crime occurred.”

Kathryn’s body was found near the Berlin Reservoir on Aug. 25, 1994, four days after she was last seen near Alliance, Ohio. She had been strangled.

The remains of Sarah were  found about a half-mile away on Nov. 4, 1994, five months after she was reported missing from Rochester, Pennsylvania, a Pittsburgh suburb about 50 miles away. Her remains weren’t identified until 2003.

The FBI is looking for DNA and other evidence to determine who killed the girls, and whether their deaths are related.

Kathryn’s mother calls being told of her daughter’s death a “horrible day" and says she is still searching for answers.

“They're out there, they're out there, and they can't have a conscience to still be there and 21 years later not think about what they did,” Janet Menendez told Fox 8. “If they find out who killed her, she's still going to be dead. Nothing's going to change for me. My life will still be the same. It's just those people will be off the street because if they did it to one person, who's to say what they've done since then.”

The station said authorities are also hoping the renewed focus on the cases will drum up tips.

The Associated Press contributed to this report.

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