A former member of the now-suspended Delta Upsilon fraternity had charges of sexual assault dropped after the Whitman County Prosecutor’s Office determined there was not enough evidence to satisfy the burden of proof needed in criminal proceedings.

Dan LeBeau, the Whitman County chief deputy prosecutor who was overseeing the case for the county, said investigative efforts fell short of proving the assault happened beyond a reasonable doubt, which is the standard for criminal trials.

“It was a very thorough investigation by the Pullman Police Department,” LeBeau said. “[We] could not prove any crime beyond reasonable doubt.”

Pullman PD announced in January it had recommended a charge of second-degree rape, which stands as a Class A felony in Washington, Pullman PD Cmdr. Chris Tennant said.

The investigation was “lengthy,” Tennant said. He also said the investigation was prolonged due to a lack of eyewitnesses to the alleged rape, forcing them to use witness statements from times before and after the alleged incident. He also said a six-month wait on DNA results from the state testing lab contributed to the length of the investigation.

The alleged sexual assault was reported as happening on the weekend of Sept. 2, 2016, at the now-suspended Delta Upsilon fraternity house. The house has since been occupied by a different fraternity.

The WSU Interfraternity Council voted 23-1 to suspend the chapter approximately two weeks after news of the allegations broke. The decision also came after allegations of a drugging at the house, an investigation which was dropped due to a lack of evidence in October 2016.

Reporting in this story was contributed by Evergreen reporter Jayce Carral.