(CBS Local) — A group of dental students and a professor from the University of Connecticut took a selfie with two severed heads while in a training workshop at Yale University last year. The incident, which Yale officials call “disturbing” and “inexcusable,” has forced the school to look at its policies regarding taking photos in private, medical areas.

The selfie was taken in June at the Yale School of Medicine during a surgical workshop and shared in a private group chat. The Associated Press obtained the photo from a member of the private group. Dr. Flavio Uribe, head of orthodontics at UConn Health, was identified as the teacher in the photo. Uribe was a visiting associate professor at the Yale School of Medicine and was reportedly showing the students how to place screws in the cadaver heads at the time. Fellow Yale School of Medicine professor, Dr. Lawrence Rizzolo, called the incident “an egregious violation of Yale policy.”

“Somebody unfortunately took a photo,” Uribe said, according to CBS News. “It was so quick. I wasn’t sure of the surroundings or scenery at that point.” While Yale officials said there are signs clearly posted forbidding picture taking in the labs, the school is now making students agree in writing to the ethical standards of conduct.

“The faculty member who was involved in the training at which the photograph was taken has been informed of Yale’s expectations in this regard,” Yale spokesman Thomas Conroy said. A UConn Health spokesman declined to say whether anyone was disciplined.

[H/T CBS Connecticut]