Genetic searches on 23andMe and similar ancestry sites have identified three dozen half siblings with the same biological father—an Indianapolis-area fertility doctor who assured women decades ago that he was using sperm from either their husbands or from anonymous donors that matched certain criteria.

The fecund doctor, Donald Cline, has since admitted to lying to patients and using his own sperm to inseminate them. It is still unclear just how many times he used his own sperm. But court documents state that he admitted to one of his biological daughters, Jacoba Ballard, that he did so around 50 times during the 1970s and 1980s , according to a report by the Associated Press.

Last week, Cline surrendered his medical license to the Indiana Medical Licensing board, which also barred the 79-year-old from ever applying for a license again in the state.

But the children of Cline’s patients say the doctor is getting off easy. Cline retired in 2009 and his license had already expired in 2017. Moreover, Cline is not facing any criminal charges in the state for lying to patients.

State investigators started looking into the case in 2014 when a group of women, including Ballard, filed a complaint with the attorney general. The doctor initially denied using his own sperm for his fertility patients, then changed his story, admitting he had indeed used his sperm. DNA testing conducted by the state also confirmed that at least two women, including Ballard, were biological children of Cline. Searches on consumer genetic testing and ancestry sites have since identified dozens of other half-siblings and connected those children to Cline's relatives.

Last December, Cline pleaded guilty to two felony obstruction of justice charges for initially lying to investigators about using his own sperm. At the time, prosecutor Terry Curry stated:

Not only did Dr. Cline abuse his position of complete trust with his patients, his decisions will have lasting impact through generations of the impacted families.

But Curry admitted that “there were significant limitations to how a criminal case could proceed against Dr. Cline.” Prosecutors said that there were no Indiana laws that specifically prohibit fertility doctors from using their own sperm.

The prosecutor’s office told The New York Times this week that Cline is no longer under criminal investigation, but they declined to answer whether he was ever investigated for fraud.

Ballard and other biological children of Cline are now pushing state lawmakers to pass a law explicitly prohibiting doctors from using their own sperm in cases like this.

“I want laws changed, I want medical professionals to be held accountable,” Ballard told the Times. “As far as peace of mind? I’ll never have that.”