Good job Dedpanman on putting together many facts in the M.O. vs Signature filter.
Would like to break up my responses into separate posts, beginning with 'how do we know that?'
'His motive for her abduction was primarily sexual.'
'He fled Queensville with Christine.'
'He had a knife' or did he take her somewhere where he had a knife?
How do we know why he chose the manner of death that he did?
I shall attempt to address your points in order:
'His motive for her abduction was primarily sexual.'
This is an assumption I made based on research. I did qualify my statement as primarily sexual but this quote below elaborates further on how the sexual component of a child abduction might relate to power, control and sadism.
From The Abduction of Children by Strangers in Canada: Nature and Scope by Marlene L. Dalley, Ph.D. and Jenna Ruscoe, B.A., M.Sc.
The most common motive of child abduction which results in murder is sexual gratification (Boudreaux et al, 2000, Asdigian et al, 1995). The findings of the United States National Incidence Studies of Missing, Abducted, Run-away, and Throwaway Children (NISMART) reported that two thirds of non-family abductions involved sexual assault (Finkelhor et al, 1990).
This finding, however, is in contrast to other findings which suggest that only very few abductors are motivated by sexual desire but they consider the sexual act itself a violent way to achieve a sense of power (Tedisco & Paludi, 1996). Females, particularly Caucasian females, are more often the victims of these types of crimes. "Sex offences occurred most often in older school age children by non-family male offenders" (Boudreaux et al, 2000). Because they are more independent and free to move about unsupervised, older school age children are commonly targets for abduction.
Some abductors are sexual sadists, that is an individual driven to pursue their fantasies. These fantasies may include domination, pain, control, and humiliation as the focal points, and the crime is typically well-planned (Hazelwood et al, 1992)."
So, thats what Im thinking.
'He fled Queensville with Christine.'
Perhaps I should have said,
fled from the point of abduction with Christine. I admit, I still (either correctly or incorrectly) assume that he headed for the Sunderland area immediately after taking her.
'He had a knife' or did he take her somewhere where he had a knife?
Good point. Based on the personalities of MacPhail and Foster and various other criminals Ive studied, I lean towards him having a knife on him or in his vehicle most of the time. I freely admit that there is no evidence for this. Just a hunch that could be wrong.
How do we know why he chose the manner of death that he did?
We dont. (I don't.) In fact, we dont even know which set of injuries caused her death (or combination of injuries). When I play the scenario through my mind, however, I always see him doing the stabbing first, as the injuries suggest a frenzied, loss of control action. Then I imagine the other things happening (cutting the breastbone, the decapitation) as they seem to require more control.