The perpetrator may even have a documented prior criminal history involving physical or sexual assaults of victims with some of the same characteristics as the current series of victims. More likely than not, the perpetrator is a product of a home in which children witnessed physical abuse of their mother and/or experienced physical abuse themselves.

The fact that all but one victim shows evidence that the force used in the murder far exceeded that necessary to achieve death by strangulation suggests that the perpetrator possesses a significant amount of anger, even rage, at someone represented by his victims. The fact that all but one of the victims suffered a broken neck suggests that the perpetrator is more likely under the age of 50 than older, and more likely either a large or physically robust individual or both. Suggested...

Finally, the pattern of phone notification to law enforcement also suggests a history of defiance to authority.
Sources Consulted

Gerrig, R., Zimbardo, P. (2005) Psychology and Life 17th Edition. Boston: Allyn & Bacon.

Innes, B. (2007) Serial Killers: The Stories of History's Most Evil Murderers. London: Quercas.

Schmalleger, F. (2001) Criminal Justice Today: An Introductory Text for the 21st Century. Hoboken, NJ: Prentice Hall