Gaston County police said they did conduct a national search for Madelyn Thomas in 1990. They said communications between police departments was not as good then as it is now, and DNA evidence wasn't as reliable.
Officers from both sides of the state line have a lot of backtracking to do to solve this 23-year-old murder case.
Gaston County police are starting by asking for help from people like Darrell Whitesides. In 1990, Madelyn Thomas lived near him in a now-vacant Gastonia home.
"She was a likable person. She was friendly," Whitesides said.
Police know that Thomas had past arrests for prostitution.
They need to know who she hung around with, who she feared before she vanished in July 1990.
The next month, her dismembered and badly decayed body was found in Spartanburg County, S.C. It appears she was stabbed.
"Whoever done it is crazy. Crazy, uncalled for," Whitesides said.
Police didn't know that the disappearance and stabbing were connected until this spring.
That's when advancements in DNA testing allowed officers to detect some of Thomas' chronic health issues in the genes of the remains. Now officers need information that can't be found in test results.
"It's going to be difficult, no way around that, trying to recreate events that happened 23 years ago," said Capt. Jay Human with Gaston County Police Department.
Human took the original missing-persons report in 1990. Thomas' husband, who filed the report, died in 1998.
"We weren't able to develop any fruitful lead early on," Human said.
Though it is a murder investigation, officers have no idea when or where Thomas was killed or who killed her.
Thomas' immediate family members live in Texas, Pennsylvania and Baltimore. The coroner said that they're happy to hear her remains were positively identified, but they're eager to see the person responsible for her death brought to justice.