For decades, dozens of human skeletons have sat nameless in medical examiners' offices across Minnesota.

The state Bureau of Criminal Apprehension (BCA) is gambling that advanced DNA techniques will soon link those unidentified remains to the names of people who have been missing for as long as 40 years.

But for that to happen, state officials need relatives of long missing Minnesotans to step forward and let investigators take a simple swab from the inside of their cheeks.

That DNA will then be compared to DNA from at least 100 remains found in Minnesota from the 1970s to the 1990s.

"Without the participation of family members, this effort cannot succeed. We need families to come forward, no matter how long ago their loved one went missing," said Catherine Knutson, director of the BCA forensic science laboratory "We need to give these people back their names and get them back to their families."

.More than 20 years after his adult son Daniel left his girlfriend's Maplewood home and never returned, Elliott Karpeles said he has come to the point where he tries to not dwell on what could have happened.

"I only have closure now because I don't know anything," said Karpeles, 78, from his home in Santa Barbara, Calif. But, he added, "If I had any more information, as sad as it might be, there would be definite closure."

Karpeles said he plans to contact state authorities to see if DNA testing could be used in his son's 1992 case.

Forensic scientists first started using DNA to test remains around the year 2000, but within the past few years DNA extraction and testing capabilities have become more sensitive, said agency spokeswoman Jill Oliveira.

Forensic testing currently available allows scientists to derive DNA from old remains even if they are in poor condition.

More than 11,000 people are reported missing in Minnesota each year, with most located soon after being reported, Oliveira said. The BCA has information on 171 individuals who have been missing for more than a year. But more are believed to be missing, though their families have yet to report them, she said.

DNA obtained from the remains will be entered into the FBI's Combined DNA Index System where it will be compared with family member samples.

In addition to the testing, descriptive information about missing and unidentified people will be entered into the National Missing and Unidentified Persons System.

The goal of the initiative, which is expected to take more than a year to complete, is to identify all of Minnesota's unidentified remains or to at least derive DNA profiles which can be entered into the federal database for future comparisons. They were collected from medical examiners across the state.

The BCA is continuing to contact offices for additional remains, where they often sat unclaimed when they weren't able to be identified.

The effort is funded through a $363,485 grant from the National Institute of Justice. The grant money covers anthropology exams, the DNA testing, one full-time position plus overtime for existing positions to do the work, and research and development, Oliveira said.

According to the National Institute of Justice, 40,000 sets of unidentified remains are held in medical examiners offices across the country.

And about 15 percent of unidentified remains have been entered into the FBI's missing person database.

Mary Hudalla, 78, who lives with her husband in St. Paul, had chased down unidentified bodies for years after her 21-year-old son Bernard, who suffers from schizophrenia, vanished in 1983.

"To not know, for some people, is very very difficult. For me personally, I think he's dead," she said Thursday afternoon.

But Hudalla said she wouldn't pass up the chance to see if DNA testing might work in finding her son.

"Perhaps. Perhaps," she said.

Nicole Norfleet • 612-673-4495

Twitter: @stribnorfleet