EXETER, R.I. (WPRI) – A newly released arrest report reveals how police zeroed in on an Indiana man accused of sexually assaulting two young girls in Exeter more than 35 years ago.

Frank Thies, 66, of Terre Haute, was arrested last month and charged with one count of first-degree sexual assault and two counts of first-degree child molestation. He’s accused of forcing the 11 and 13-year-old girls into the woods at knifepoint, making them take off their clothes and assaulting them.

The documents obtained by Target 12 through a public records request include the original 1987 state police “complaint report” from the April 12 incident.

“A female calls in a frantic voice stating that two young girls have been raped,” a trooper wrote in the report. “The man who did it ran off into the woods … In the same breath she said have a trooper meet me at Kent County Hospital then hung up.”

The report also reveals that a man who was later identified as one of the victim’s father went to a neighbor’s home asking for a gun. The neighbor told police she was afraid the man was going to kill someone.

The 1987 report included a wanted poster with a sketch of the subject identified as a white male in his late 30s with “graying brown hair.”

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“Suspect has a ‘speech difference’ possibly an accent, slight dimple or indent in chin,” the poster states.

At Kent Hospital a doctor collected evidence from the two girls for a rape kit, and their clothes were taken into police custody. For more than three decades the evidence lay dormant until 2019 when the case was reopened by state police Det. Kyle Draper.

The key evidence from the case was kept in a sealed plastic bag including the victims’ T-shirt and underwear, which was sent to the FBI crime lab. Further examination of the evidence by the state’s Forensic Services Unit and the Department of Health found additional samples that included two pieces of DNA.

In March 2020 Draper contacted one of the victims — who now lives out of state — seeking a sample from her to separate the two sets of DNA from the clothing. The unidentified victim told the detective she would be willing to respond to the nearest police department to give a sample, and said she “would still like to press charges.”

Draper spoke with the other victim as well, who would later take investigators to the wooded area where the rape occurred, telling him “she was willing to cooperate with the investigation and vividly remembers the incident.”

Using the DNA from one of the victims, police were able to separate the samples and submitted the information to Identifinders International in January 2022. The company uses information from genealogy websites to try to identify suspects in cold cases. Forensic genetic genealogy was used to capture the so-called Golden State Killer, who murdered 13 people and raped dozens of women in the 1970s and 1980s.

The results identified three possible suspects, all of them brothers and matched through their parents, and also determined the suspect was of Polish descent.

Of the three, only one – Frank Joseph Thies – had any ties to Rhode Island.

“From April 11, 1987, to June 12, 1987, Frank Thies reported to the Naval Justice School located in Newport, Rhode Island,” Draper wrote in the arrest report. “He went to the school to obtain training to become a Line officer which is similar to a paralegal.”

The report states Thies was married at the time of the rape.

Meanwhile in Indiana, state police detectives had “recovered several items that were discarded by Frank Thies.” Draper and another detective flew to Indiana to gather the evidence and brought it back to Rhode Island for testing at the state health lab on Orms Street in Providence. On Oct. 6, DNA from three of the items – a fork, drinking glass and Styrofoam cup – came back to a match to the evidence collected in 1987.

Six days later a grand jury was convened to review the evidence and issued an indictment of Thies. The following week Draper and three other state police detectives were at Thies’ Terre Haute doorstep with an arrest warrant in hand.

The report states Thies agreed to speak with investigators and the interrogation was recorded. Details of what Thies said is not included in the report.

They also had a search warrant to obtain a DNA sample by swabbing the suspect’s mouth. On Halloween the results came back: his DNA matched the evidence from the 1987 crime.

Tim White (twhite@wpri.com) is the Target 12 managing editor and chief investigative reporter at 12 News, and the host of Newsmakers. Connect with him on Twitter and Facebook.