Matthew was a Major in the US military who was the father of twin girls Amanda and Helen Collins. He was looking into finding a way to purge post-traumatic psychological damage from a soldier's mind. He used Helen to experiement on after the US gov. denied him permission to experiment on others. Over time, he tortured his daughter.
Sometime in 1987, Amanda wanted to save her sister, so she attempted to run away and take Helen with her. Matthew stopped them and sent Helen away while he disciplined Amanda. But Helen returned slit his throat and stabbed Amanda in a fit of rage before she set their house on fire. Helen would later assume her sister's idenity and ironically continued his work until she was eventually captured and put in jail for the rest of her life.