The Supreme Court has acquitted a college professor of groping a high school girl on a train, marking the first time the top court has overturned a guilty verdict in a molestation case.

The Tuesday ruling by the Third Petty Bench overturned lower court rulings that threatened to put Masahiro Nagura, a professor of Japanese intellectual history at National Defense Medical College, in prison for 22 months.

Nagura, 63, has been suspended from teaching since the indictment. He said after the ruling that the top court's verdict "rid me of the feelings of distrust I had against the judicial system. . . . I couldn't stop crying. All I was able to say to my wife was 'Thanks.' "