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R.I. State Police crack 1980s cold case, thanks to forensic genealogy

A 66-year-old Indiana man faces first-degree sexual assault and first-degree child molestation charges in the Exeter, R.I., rape case.

Frank Thies, 66, of Terre Haute, Indiana, was ordered held without bail in rapes of two girls in Rhode Island in 1987. Public Defender Stephen M. Peltier stands beside him in court.Amanda Milkovits/Globe Staff

EXETER, R.I. — A former military man from Indiana who’d been at the Naval Justice School in Newport has been charged with raping two girls at knifepoint in the woods of Exeter more than 35 years ago.

Frank Joseph Thies, 66, of Terre Haute, was ordered held without bail during his arraignment at Washington County Superior Court on Thursday on charges of first-degree sexual assault and first-degree child molestation. If convicted, he could face life in prison.

Rhode Island State Police Colonel Darnell Weaver said the lengthy investigation included genetic genealogy using the rapist’s DNA, which helped lead them to Thies, who had no ties to Rhode Island — except for reporting to the Naval Justice School the day before the two girls were assaulted.


During the arraignment, Assistant Attorney General Tim Healy called the case “every parent’s worst nightmare.”

As Healy described what happened in the woods of Exeter on April 12, 1987, Thies looked away from Judge Melanie Wilk Thunberg, and up at the ceiling, and then bowed his head.

An 11-year-old girl and 13-year-old girl were playing tennis in front of a house on Stony Lane, when a stranger came upon them, Healy said in court. The man pulled out a knife and grabbed the 11-year-old girl, and as he dragged her into the woods, he yelled at the older girl to come with them, Healy said.

If she didn’t, he threatened to kill the younger girl, Healy said.

Once in the woods, the man sexually assaulted the 11-year-old girl and then raped the 13-year-old, Healy said. Before he left, the man threatened them again, the prosecutor said, but the girls ran and told one of their mothers.

Investigators had collected physical evidence that was developed to include the suspect’s DNA profile, which the State Police said was compared over the years with several different suspects.


But there wasn’t any match, and the case went cold. The State Police tried again in 2005 with the advent of the Combined DNA Index System, also known as CODIS, but there weren’t any leads, the State Police said.

Then in 2019, detectives in the special victims unit reopened the case. The Rhode Island State Police Forensic Services Unit with the state Department of Health reexamined the physical evidence and requested genetic genealogy investigation to help find the suspect.

They turned to Identifinders International, a California-based organization of expert forensic genetic genealogists that collaborate with law enforcement to investigate and solve cold cases.

Linda Doyle, a senior forensic genealogist at Identifinders International, said that this case was the 11th one she’s solved over the last year and a half.

First, law enforcement has to make sure the DNA evidence is suitable for forensic genealogy, by having it retested and resequenced at a third-party lab, Doyle said. Then, they create a profile that is uploaded to two genealogy databases, GEDMatch and Family Tree DNA, where users can opt to allow law enforcement to seek matches.

Often, as in this case, the DNA evidence they upload will come back with thousands of potential, distant matches — think third or fourth cousins, Doyle said.

That’s when she goes to work, building the family trees, a process that she said can her take less than a week. “It is straightforward,” Doyle said. “If you are skilled enough and find the right lines, you will come to the right hypothesis, and it should bring you to the unknown subject’s mother and father.”


From thousands of possibilities, Doyle narrowed down potential investigative leads.

The State Police said that they got a lead this August that the suspect in the rapes was likely one of three brothers originally from Erie County, N.Y., who all had military service.

Detectives worked with the Naval Criminal Investigative Service and learned that the oldest brother, Frank Thies, had reported to the Naval Justice School in Newport the day before the girls were assaulted.

With help from the Indiana State Police, the detectives got a discarded sample of Thies’s DNA. A test showed a match to the DNA from the man who’d raped the two girls in Exeter in 1987, according to the State Police.

A statewide grand jury indicted Thies, and the Indiana State Police arrested him on Oct. 19 as a fugitive from justice.

When the Rhode Island State Police detectives spoke with Thies, “he said he was present that day and had a knife,” Healy said.

The prosecutor requested that Thies be held without bail, “based on the severity of the crime, that this is every parent’s worst nightmare and the trauma caused to victims.” He also emphasized that Thies, a former member of the military, had no ties to Rhode Island, aside from that one time he was stationed in Newport in 1987.

Just this April, Thies had joined the Terre Haute Breakfast Optimist Club, a chapter of Optimist International, a volunteer organization with a mission to value all children and help them develop to their full potential.


David Shields, a member, said Thursday that Thies had been sponsored by another longtime member, “so we assumed he had a good background.”

The club last saw Thies at a meeting in September, he said. Then, a few weeks ago, club chairman Terre Haute police Sergeant Brad Newman told them that Thies had been arrested — and why.

“It was just, ‘Wow.’ We were in disbelief. It happened so long ago,” Shields told a Globe reporter.

When the judge asked Thies about his address, he hesitated. He said that his family and friends cleaned out his apartment in Terre Haute after he was arrested last month.

Thies is now living at the intake center at the Adult Correctional Institutions, pending a bail review on Nov. 23.

Thies served in the US Marines and US Navy, and is believed to have lived in New York, North Carolina, South Carolina, Florida, Virginia, Mississippi, Tennessee, Washington, D.C., Texas, Italy, and the United Kingdom.

The State Police ask anyone with information about Thies to contact the special victims unit at 401-764-5394.

The State Police worked with the Indiana State Police and the Indiana attorney general’s office, and also with the Virginia State Police, the New York State Police, the Naval Criminal Investigative Service, the FBI’s Behavioral Analysis Unit, the state Department of Health, and Identifinders International.


This story has been updated with an explanation of the forensic geneology process from Identifinders International, details from Frank Thies’s arraignment, and a comment from a member of the Terre Haute Breakfast Optimist Club, to which Thies belonged.

Amanda Milkovits can be reached at amanda.milkovits@globe.com. Follow her on Twitter @AmandaMilkovits.