American University has ended an investigation into anti-Semitic vandalism discovered in September without identifying a suspect, The College Fix reported.

On September 7, a student at the Washington DC university found two swastikas, Nazi SS bolts and a Star of David carved into a bathroom wall.

“The investigation is inconclusive regarding who is responsible for the graffiti, their intent, or when it occurred,” American University President Sylvia Burwell wrote in an email to staff and students. “It is possible that the graffiti may have been in the bathroom stall for some time, as there was no evidence of fresh carving or shavings where it was found.”

Burwell said that “the appearance of such vile sentiments causes great pain, and our priority is to support our Jewish community members and effectively address bias incidents.”

She added that interviews had proven inconclusive, yielding “no further information about the source of the graffiti or when it occurred.”

“While the investigation may be inconclusive, the pain caused by the graffiti is real and unacceptable,” she said.

The incident was investigated by American University Police. Washington DC police were not involved.

In her message, Burwell apologized for how the incident was handled and for causing “additional hurt.”

“We must do better in these difficult situations, from educating about the terrible history and ongoing impacts of anti-Semitism to how we communicate about these matters,” she said. “We sought to be cautious in our communication as the investigation was in its early stages and information was still being collected and reviewed.”

She wrote that regardless of the fact that they did not discover who was behind the incident or their intent, the vandalism’s “existence caused pain and trauma for members of our community.”

“We are concerned about any behavior or actions that targets our Jewish community at [American University], and we are committed to confronting anti-Semitism in all forms,” Burwell said.