In a 3-2 decision, the Supreme Court on April 14 ruled that a university professor was innocent of the charge that he had molested a high school girl in a packed train, overturning lower court rulings that had found the professor guilty and sentenced him to a 22-month prison term. The top court's Third Petty Bench found that there was room to doubt the reliability of the girl's depositions. The ruling will have a great impact on the investigations and trials of similar molestation cases.

The 63-year-old National Defense Medical College professor was charged with molesting the then 17-year-old girl in an Odakyu Line train on April 18, 2006. He consistently maintained his innocence. The girl testified that the professor began molesting her on the train before it arrived at Seijo Gakuen-mae Station. After she was pushed out of the train as passengers disembarked at the station, she then boarded the same car and stood in front of the professor, whereupon the molestation began once again. The bench's majority opinion said there was room to doubt the reliability of her testimony because she did not try to stop the molestation and because it was unnatural that she would board the same car if she had just been molested there. The court did not go so far as to say her testimony was fabricated. Instead, it upheld the principle that punishment should not be meted out when guilt is uncertain.

What is noteworthy about the case is that the top court set a guideline for the investigation of molestation incidents on crowded trains. It said that in such cases it is difficult to obtain evidence beyond the victims' depositions. It went on to note that if a person is accused of molestation, it is very difficult for that person to defend himself or herself. Thus the court called for "especially careful investigations" in such cases.