What is the main conflict in Kiss the Girls by James Patterson?

Kiss the Girls is a mystery/thriller tale of obsessive kidnapping and murder. Casanova, a serial killer and kidnapper, has killed several women in the vicinity of the University of North Carolina. In addition to the girls that have been killed, several others are missing. Among the missing girls is the niece of renowned detective Alex Cross. Cross, through his connections at the FBI, is allowed to work on the case. The killer seems to have a taste for extremely beautiful women and is known for his near perfect crimes.