all i can remember is it's from 1996 (the CBS era) and the girl's name was Rochel


anyone know if it was ever solved?

That sounds to me like the 1994 murders of Michael Johnston and Rochelle Robinson, except that the former was 25 years old, not 45. Although you were correct when you said it aired in 1996, UM was still on NBC at the time.

You can find the case at the official UM web site (more easily at this link: www.unsolved.com/murder.html).