"48 Hours Mystery" helps solve a 20-year-old cold case... Three women brutally murdered from Chicago to Los Angeles and an alleged serial killer on the run. Maureen Maher has the dramatic developments. Last spring, "48 Hours Mystery" reported on the 1993 murder of a young woman named Tricia Pacaccio. Now, because of that broadcast, we can report that there is finally a breakthrough for a family that has been waiting nearly two decades for justice.