Less than a week after federal agents arrested a Cincinnati-area doctor in connection to a 1989 rape cold case, new court documents claim the 66-year-old was not a one-time offender, preying on multiple women as a "serial sexual predator" for more than three decades.Frederick Tanzer is a medical doctor who has lived and practiced medicine in Ohio, Kansas and Colorado, according to the U.S. Attorney's Office.According to a criminal complaint, Tanzer was identified earlier this year as a prime suspect in a 1989 Cincinnati rape. Investigators said they were able to get Tanzer's DNA from a coffee cup that he had thrown away and match it to DNA on the victim's underwear. Authorities said Tanzer knew the victim. When he was recently brought in for questioning, FBI agents said he lied to them, including denying having seen or interacted with the victim on the date she was raped. Tanzer was charged with one felony count of making false statements to the FBI last week and placed in the custody of the US Marshal Service. He spent less than a day in the Montgomery County Jail before transferring to the Shelby County Jail. Inside a federal courtroom in Dayton on Monday, Tanzer waived his pretrial detention hearing, choosing not to oppose federal prosecutors' request that he remain behind bars pending his trial. A magistrate then ordered his detainment. "The charge that he faces is essentially lying to the FBI, which is similar to what Martha Stewart was charged with," said Patrick Mulligan, Tanzer's attorney. "He's not charged with any other offenses and I'm not aware that any other offenses are going to be filed at this point, so that's the only thing that we are looking at."According to court documents, the FBI received verbal confirmation from the testing laboratory on Friday that the DNA taken from Tanzer during a search warrant on Dec. 11 is a match for the DNA left by the attacker in 1989.Agents found items including cable zip ties, restraints, a gag and a black hat inside Tanzer's dresser drawer when they searched his home last week, court documents claim. Agents also obtained a follow-up search warrant for electronic devices of interest seized from Tanzers home; the review of these devices is ongoing.Mulligan told WCPO he's optimistic the charge against Tanzer will be dropped once more information is released and discussed in future court proceedings. He suggested that even if federal prosecutors wanted to file sexual assault charges, the statute of limitations would prohibit them from doing so. In Ohio, sex crimes that occurred in the 1980s could only be prosecuted up to six years from the time of the crime. The 1989 rape Tanzer is charged in connection with happened 35 years ago."It's beyond the statute of limitations," Mulligan said. "It's not really chargeable."Still, federal prosecutors detailed more allegations against Tanzer in his motion for pretrial detention. The 16-page document claims that Tanzer not only perpetrated the violent rape in 1989 but that it was likely not his first sexual offense."In the 35 years between that brutal attack and today, Tanzer went back to his life, hiding behind the prestige and authority of a white doctors coat. But, as the horrifying circumstances of his rape of the Victim suggest, he was not a one-time offender. There is evidence that, behind closed doors, he continued his pattern of sexual violence against the women in his lifethat he secretly, and repeatedly, drugged both [sic] and [sic] to the point of blacking out, and that he then had sex with them without their consent," the motion reads. Federal prosecutors wrote that their claims refer to three victims that the government is aware of. "Every aspect of the 1989 rape together with evidence recovered from a search of Tanzers home gives further reason to believe that he is a serial sexual predator," prosecutors wrote.The FBI confirmed with WCPO that they believe there could be more victims. They're asking anyone with relevant information to come forward.