WASHINGTON (CNN) -

A passenger accused of posing as an airport security agent and taking women into a private screening room will not be prosecuted.

Eric Slighton, 53, was arrested July 15 at San Francisco International Airport after being seen motioning women into the room where private pat-downs are conducted, authorities say.

"Officers determined that Slighton was exhibiting the signs and symptoms of public intoxication and placed him under arrest," according to a release from the San Mateo County Sheriff's office.

The district attorney reviewed the case and determined there was not enough evidence to convict Slighton on any charge.

"We don't know if anything improper did happen" in the screening room, Karen Guidotti, the San Mateo County District Attorney's Office Chief Deputy told CNN. "We were never able to locate those women."

There are no cameras inside the small rooms, and there is no local statute against impersonating an airport security screener, she said.

Simply being drunk was not enough to prosecute Slighton either.

"Clearly there was evidence that he was intoxicated, but the standard would require us to prove that he was so intoxicated he was unable to care for himself," Guidotti said.

Airport security at San Francisco International is operated by a private company under the supervision of the TSA.

"TSA is aware of the alleged incident and is cooperating with law enforcement," TSA spokesman Ross Feinstein told CNN.

Slighton has homes in San Francisco and Hong Kong and is a director and partner of the banking and investment company Aktis Capitol Singapore, according to the firm's website.

The South China Morning Post reported his father in law is Tung Chee Hwa, the first chief executive and president of the executive council of Hong Kong after it was returned to China.

"In my view, this was an unfortunate event that should not have happened," he said in a statement to the newspaper shortly after the arrest. "I see Eric as a good husband to my daughter and a responsible father to my grandchildren."