Dateline: Unmasking the Monster - Timeline breakdown of the Dana Beatty case

Dateline's new episode titled Unmasking the Monster revisits the horrific r*ape of a 29-year-old woman named Dana Beatty, who is now 67, by a masked intruder at her Cincinnati home on August 1, 1989. The masked man held a knife to her neck, covered her face with tape, tied her to a bed, and attacked her for hours.

On the same day of the incident, Dana Beatty reported the r*pe to the police, and after that, investigators started working for years to solve the case. According to a former Cincinnati detective named Charlie Beaver, they even looked into a local officer who was first considered a possible suspect. The DNA evidence revealed that the intruder was a local physician who was also the husband of Dana's closest friend.

However, another Cincinnati police detective, Jeff Smallwood, revealed that the attacker could not face r*pe charges because the 6-year time limit for the crime had already expired by the time charges were considered. Even the 2015 change in the state law did not reopen her case.

Continue reading more about the story.

The full timeline of the Dana Beatty case in Dateline

August 1, 1989

The Dateline showed that when Dana Beatty came back from work, the masked man was inside her home. He wore a black suit that covered his whole body, black gloves, and a mask that hid his face.

Centre Daily Times revealed that Tanzer used a knife from Dana's kitchen to threaten her and then wrapped her face in thick white tape so that she couldn't identify him. The man then tied her to the bed and s*xually assaulted her for several hours. Dana quickly reached out to the police and gave a statement about her assault.

In the same month, the forensic experts recovered semen from Dana Beatty's dress and preserved it. However, the forensic methods available at that time couldn't provide clear leads. Investigators pursued several false directions, including suspicion of a local police officer who was later proven to have a strong alibi.

2024: The truth came out

The Dateline revealed that in early 2024, the beloved daughter of Dana, Andra Beatty, reached out to the Cincinnati Police Department and asked investigators to review her mother's unsolved case.

Modern forensic testing connected the crime scene evidence to a local doctor. The discovery shocked Dana because the forensic reports revealed that the DNA obtained from a discarded coffee cup was of her best friend's husband, Tanzer.

According to the court documents, Tanzer received his medical license two months before the attack and then practiced medicine for the next 30 years in several states, including Colorado, Ohio, Arizona, and Kansas.

When Tanzer was confronted with the clear DNA match, he asked for a lawyer and was taken into custody. Since the 6-year statute of limitations for r*pe in Cincinnati had expired, the attacker didn't face r*pe charges.

September 2025

The Dateline exposed that in this month Tanzer pleaded guilty in U.S. District Court to three counts of making false statements to federal agents, and in doing so he admitted to carrying out the 1989 attack.

January 28, 2026

A federal judge sentenced Tanzer to the maximum penalty of 180 months. U.S. Attorneys publicly identified him as a suspected serial r*pist, and the FBI began searching for possible additional victims from the time period he practiced medicine in other states.

October 2, 2026

The case gained national attention when NBC's Dateline aired a special episode called Unmasking the Monster. Dana Beatty used the true crime series to call for ending statutes of limitations on s*xual assault across the nation.