Beauty and the Beast (1987)

A slasher that kills with claws and leaves the victims looking as if they were mauled by a bear is on the prowl. He attacks on the subway. Most of his victims are older. When Catherine finds out about the case she starts to suspect Vincent as she remembers how he rescued her from the attackers in the safe house. She talks to him about it. In a way this upsets him, but he tells her that it is not him. She is relieved when she finds out for sure that it is not him. Especially since the true culprit is a very unexpected source.