FBI links doctor to brutal Ohio sexual assault after decades of fear

Kevin Grasha, Cincinnati Enquirer

Wed, January 14, 2026 at 5:15 AM UTC

5 min read

In 1989, a 29-year-old woman was attacked in her home by a man wearing a black, full-body spandex suit, black gloves and a mask that covered his face.

He wrapped thick, white tape around her head and face, from the top of her forehead to the base of her nose, so she couldn't see. He forced the woman into her bedroom and used her own stockings to bind her to the bed frame.

He never spoke, and only once, after she screamed, said "Shh," as he pressed a knife against her neck.

Over five and a half hours, he repeatedly sexually assaulted her. In between attacks, she heard him sitting in a rocking chair or listening to messages on her answering machine, which led investigators to wonder if he knew her and his voice might be on the tape.

For 35 years, the case remained unsolved, and the woman lived in terror, always wondering if her attacker might return. He left a handwritten note for her on a newspaper, threatening her:

“No police or I’ll be back Mis IBM.”

The woman worked for IBM at the time. Then in January 2024, after Cincinnati police and the FBI re-examined the case, the woman learned who the attacker was.

He was a doctor and the onetime husband of her best friend. His voice, in fact, had been on the answering machine tape.

"I'm sorry about your granddad." he said in a message about two months before the attack. "I'm thinking of you."

Frederick Tanzer, now 67, could not be charged with rape because the statute of limitations in place at the time had expired.

But when investigators in 2024 questioned Tanzer at his Sycamore Township home about the 1989 attack, he lied, denying he had seen or interacted with the woman that day.

Tanzer’s DNA – taken from a Starbucks coffee cup he had thrown in the trash – conclusively matched DNA from the scene.

Surveillance photo of Frederick Tanzer outside a Bureau of Motor Vehicles office in Milford in April 2024.

On Jan. 12, Tanzer appeared in federal court in Dayton to be sentenced for making false statements to federal agents, charges he pleaded guilty to last year. A prison sentence was not imposed. U.S. District Judge Michael Newman will do that on Jan. 28.

There is a lot to consider.

Tanzer himself admits that he was the attacker. But he will be sentenced on the making false statements charges. Prosecutors, who consider Tanzer a serial rapist, are seeking a 15-year sentence, the maximum possible.

Prosecutors pointed out that when Tanzer was arrested in December 2024 at his home in Sycamore Township, investigators found a gag, restraints and zip ties in his dresser.

Tanzer's attorney asked for a sentence between about six and seven years.

'Unstable' and 'dangerous'

In court on Jan. 12, at least 40 family and friends of the woman packed the courtroom. Among her supporters was the best friend who is Tanzer's former wife and the two children she had with Tanzer.

The two children, now adults, have described their father as manipulative, and according to prosecutors, were frightened of him. Both had been estranged from him for years before his arrest.

One said in court documents that Tanzer was unstable, delusional, dangerous and "doesn't value human life or autonomy."

Both Tanzer's ex-wife, who divorced him in 2008, and current wife say that he drugged them before having sex with them.

He has not been charged in connection with those allegations.

Woman describes life after attack

The woman who was attacked in 1989 spoke at length in court on Jan. 12.

She described how what happened in the Columbia Tusculum condominium had changed her life forever. She has been in therapy for decades, exists in a chronic state of anxiety and has suffered from post-traumatic stress disorder, chronic insomnia, night terrors and panic attacks.

She said she can't sleep in the dark. She damaged teeth from chronically clenching them. Her husband has learned to announce his presence if he's walking up the stairs or entering a room, so he doesn't startle her and cause a panic attack.

"I'm in a constant state of elevated alert mode," she said.

Despite that, she said she continues to fight and refuses to let Tanzer win.

She noted that in the years after the attack, when Tanzer was still married to her best friend, she sometimes saw him socially.

Tanzer had even attended her wedding in 1992.

"I remember he stood front and center," she said.

She recalled wondering "why he was looking at me that way … like he was studying me."

The last time she remembered seeing Tanzer, he was outside playing basketball with his children and others. She recalled that Tanzer became angry because the children were making more shots than him. So he "kicked a puppy" that was nearby, she said.

Tanzer makes statement in court

Tanzer's appearance has changed since he was arrested in late 2024. He has been jailed ever since. He no longer has a full mop of dyed brown hair. It's now gray and cut short.

His license to practice internal medicine in Ohio was permanently revoked in March 2025. And as part of his plea agreement, he allowed his medical licenses in Kansas, Arizona, Colorado, Indiana and North Dakota to expire.

He spoke in court on Jan. 12.

He began, saying: "I am immensely sorry and remorseful for my past actions … and have been for quite some time."

He then stood and turned toward where the woman he attacked in 1989 sat, near his ex-wife and their children.

“I am incredibly sorry for what has happened," he said. “I wish I could explain it to you.”

"It doesn't make any sense," he said, adding that part of him hoped the woman he attacked "wouldn't give up trying to find me."

"What I've done is heinous," he said.

This article originally appeared on Cincinnati Enquirer: Doctor unmasked as predator who left chilling note after brutal attack

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