[Valpal1]

Um, no it wasn't. That study happens to be the difinitive study to date on the subject. It was done by the Washingtion AG's office, partly funded by the U.S. Department of Justice and is national in scope.

If you read the intro, you'd know that.

[Valpal1]

On page 26 of the full report (PDF format) it states:

According to Hanfland et al (1997), the rarity of these types of cases has allowed a body of "commonly held beliefs" to develop that has little to no basis in fact. Hence detectives, case managers, police executives and the media sometimes operate with false assumptions and misperceptions. Homicide investigators, through no fault of their own, sometimes fail to realize that the investigations of the murders of abducted children are very different the other murders they investigate. Consequently, they sometimes make decisions about the direction of the investigation that are not "high percentage" choices. For example, some detectives believe that in any murder of a child the logical suspect is a parent and, therefore, they devote a considerable amount of resources to prove that belief. But this research shows that the parents are the least likely suspects in an abduction murder of a child. This kind of false assumption is made, in part, from lack of experience with these types of cases and because there is very little empirical research on these types of child murders and their investigations from which detectives can draw guidance. This research will help investigators make those decisions identify the strategies, and implement the tactics that will lead to the more certain and timely capture of the killers of abducted children.