Advanced DNA technology helped South Florida cold case investigators link a man known as the “pillowcase rapist” to a string of sexual assaults stemming back to the 1980s.
The Broward County Sheriff’s Office announced Tuesday that Robert Kohler, 62, had been tied to six rapes after its cold case unit, formed in 2019 to address about 350 cases with dead-end leads, was able to link the crimes using DNA.
Broward Sheriff Gregory Tony said Koehler, who has been incarcerated in Miami-Dade County since January 2020 on charges of sexual battery against one woman in the early 1980s, may have committed between 40 and 45 rapes in the greater Miami area.
Koehler is accused of breaking into the homes of women at night or early in the morning as they either prepared for bed or slept, typically with his face covered by a pillowcase or other fabric and carrying a sharp weapon, according to Broward authorities.
Authorities said he would threaten victims and their families if they said anything or screamed. He typically would tie their hands and or their feet during the assaults, said cold-case Sgt. Kami Floyd. The suspect would then steal from the apartment before making his getaway, authorities said.
The Broward Sheriff’s Office believes Koehler struck at least eight times between 1984 and 1985, according to a news release.
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While the cases garnered extensive media coverage in the 1980s, even causing officials to launch a new South Florida law enforcement task force to investigate them, the trail went cold in the 1990s.
The blood-typing technology available at the time was not enough to solve the crimes, Floyd explained.
“The task force that was put together … had no new information coming forward. There were no new cases, no witnesses, no victims and nobody who could provide anything,” said Floyd, who led the team that cracked the cold cases.
She helped launch an initiative in 2019 to reexamine the department’s sexual battery cases over the years and test all of its sexual assault kits, she said in a video interview released by Broward County Sheriff’s Office.
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Floyd, who’s worked with the sheriff’s office about nine years, said she ran across a newspaper article mentioning the “pillowcase rapist” and 40 to 45 unsolved cases in Broward and Miami-Dade counties during the 1980s and it piqued her interest.
With no dates and no victim names, Floyd said she had very little to work with. It took months of investigators digging through 500 boxes of evidence, each containing hundreds of cases. Then she found a match: A woman who was assaulted in her Pompano Beach apartment in June 1984. Soon, she had a list of cases and victims.
“I luckily did locate one that matched,” Floyd said of the first case. “With the help of our crime lab, (I located) in a freezer some specimens that belonged to other victims that had a list of (eight) names that we believed to be related to the ‘pillowcase rapist,’” Floyd said.
Advancements in DNA technology allowed the lab to retest the specimens and form a full DNA profile of the suspect, Floyd said.
Around the time her team began testing, Miami-Dade authorities announced the arrest of Koehler in early 2020.
According to an arrest warrant, investigators got their breakthrough after they obtained a DNA sample from Koehler’s son following an unrelated arrest. That sample was then linked to an assault in 1983, leading detectives to Brevard County where they followed Koehler to obtain DNA samples from objects he touched.
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“At that point, since we knew we had an identifiable person, we were able to write a search warrant and obtain another swab from Robert Koehler that matched our DNA type that we were able to pull from our specimens in the freezer,” Floyd said .
It was a match, she said.
Broward County’s cold case unit detectives worked with Broward State Attorney’s Office prosecutors to charge Koehler in six sexual assault cases, according to the sheriff’s office.
“When I found my first case, it actually saddened me to have to reach out to that victim and have her relive what had happened so many years ago,” Floyd said.
It was heartbreaking in many cases, she added, because some women had not even told their families what had happened to them. She said some of the victims told her they would need to talk it over with their families before discussing it with her.
“But when they did decide to come back and were brave enough to discuss it with me, I was very proud of them,” she said.
Their stories were all similar. They lived alone. They were assaulted at night, and the attacker apparently knew their habits, including in some cases the layout of their apartments.
Now, those victims are very relieved to know the man who attacked them may be brought to justice, she said.
“Several of them have commented that they hope more women will come forward,” Floyd said.
Floyd explained there are so many sexual assault cases in the cold case files, many from a time before records were computerized, making it difficult to match them.
“For those who haven’t come forward yet, this will bring you some closure,” she said.
Contributing: The Associated Press