Frederick Tanzer, 66, appeared in a federal courtroom in Dayton on Monday for a pretrial detention hearing, where a magistrate ordered him to remain in custody until his trial.
Tanzer, a Cincinnati-area doctor, was arrested less than a week ago in connection to a 1989 rape cold case. Court documents allege he is a “serial sexual predator” who targeted multiple women over three decades.
The U.S. Attorney’s Office stated that Tanzer practiced medicine in Ohio, Kansas, and Colorado. Investigators identified him earlier this year as the prime suspect in the 1989 Cincinnati rape. DNA evidence from the victim’s clothing matched a sample collected from a coffee cup Tanzer had discarded.
Authorities revealed that Tanzer knew the victim and lied to FBI agents during questioning, denying contact with her on the day of the assault. He has been charged with one felony count of making false statements to the FBI and remains in federal custody.
During Monday’s hearing, Tanzer chose not to challenge the prosecution’s request for his detention. His attorney, Patrick Mulligan, compared the charge against him to those faced by Martha Stewart for lying to federal agents. He stated that Tanzer has not been charged with additional crimes at this time and expressed optimism that the charge would be dismissed in the future.
Despite these claims, court documents revealed that DNA obtained during a Dec. 11 search matched the DNA left by the attacker in the 1989 case. Investigators also recovered items like zip ties, restraints, a gag, and a black hat from Tanzer’s home. A search of electronic devices seized from his residence is ongoing.
Mulligan argued that even if prosecutors pursued sexual assault charges, the statute of limitations in Ohio, which at the time only allowed prosecution within six years of the crime, would prevent them from proceeding. The assault in question occurred 35 years ago, well beyond this limit.
However, federal prosecutors presented new allegations against Tanzer in their motion for pretrial detention. The 16-page document claims he committed the 1989 rape and likely other sexual offenses over the past three decades. They allege Tanzer drugged women to the point of blacking out and sexually assaulted them without consent, referring to three known victims and suggesting there could be more.
“In the 35 years since that brutal attack, Tanzer lived his life behind the authority of a doctor’s coat,” prosecutors wrote. “Evidence suggests he is a serial sexual predator.”
The FBI has asked anyone with additional information about Tanzer to come forward, as they continue their investigation into the case.