A state judge dismissed the sexual assault case Wednesday against a Honolulu police officer accused of groping a teenage girl while on duty.

An Oahu grand jury indicted 35-year-old Kramer Aoki last November on a third-degree sexual assault charge, a class C felony punishable by up to five years in prison. The indictment says that on Sept. 6, Aoki, as a law enforcement officer, knowingly subjected to sexual contact a person in custody.

Aoki is accused of placing his hand on the breast of a teenage girl he had pulled over for speeding. After the alleged incident, Aoki let the girl go with a warning.

He challenged the applicability of the charge against him because Aoki claims the girl was not in custody.

His lawyer Thomas Otake told Circuit Judge Glenn Kim, “A traffic stop is not custody.”

Deputy City Prosecutor Lynn Costales said the girl was not under arrest, but she was not free to leave because Aoki had her driver license and vehicle registration when he touched her.