A couple of comments on your points....these are not critiques per se, just clarification of some of the information.
On how Delphi fits "the norms": remember that when we look at studies that lump all types of child/youth homicide together, we are also seeing homicides due to domestic violence/neglect, homicide due to accident (say, in the negligent discharge of a weapon), and homicide due to interpersonal drug and gang violence. So comparing Delphi to statistics of ALL child homicides makes it seem quite out of the norm (and it is...homicidal violence on a missing child is, thankfully, one of the rater homicide events). But maybe what we should be asking is, is Delphi like other known cases of child abduction and murder? We find that yes, it is fully within the pattern of a "typical" child abduction and murder. We see this when we look at studies that examine just those offenders who first abduct and then kill their child/teen victims.
A note on "abduction:" I'm not claiming they were taken somewhere else and brought back to the bridge area at a later point in time. When a victim's movements are controlled and they are taken to another location - no matter how close by - against their will or by luring, that is actually considered "abduction" in the purposes of the FBI's research into these types of killers.
When we look at studies of missing child homicides specifically, we see that Abby and Libby's case is quite close to the normal scenario....white female victim, average age 11, first contact with eventual killer was out in public, was killed within the first three hours after contact with offender, was found dead within 1/4 mile of first contact site with offender. The only outlier would be the rarity of multiple victims. This description of the "average" child abduction/murder victim is from The FBI document "Investigative Management of Missing Child Homicides":
https://www.google.com/url?sa=t&sou...CB0QAg&sqi=2&usg=AOvVaw3ztPu-MGHKSf0i7RpnVIVZ
The overall pattern seen within all child/youth homicides, and this is talked about in some of the studies cited in your initial post, is that younger children are more likely to be killed by family members. The reason is, children below about age 8 are usually more heavily supervised than older kids (especially outside) and so are less likely to be victimized by the type of killer who abducts. As they grow older and achieve some level of independence, they are more likely to be present outside without direct adult supervision. So as they get into the 8-13 age group, the relative chance that they are abducted and killed by a stranger increases. IMO this age is also attractive to this type of killer because victims this size are more easily overpowered, controlled and concealed than adult victims. After about age 12, teen homicides start to look very similar to adult homicide patterns. Older teens are mostly killed by romantic partners, friends that they argued with, criminal associates - just like adults are.
So, in fact, the reason that females age 12-14 are the rarest of ALL child homicide victims is because they usually still have more adult supervision than older teens and simultaneously less exposure to things like dating and participation in criminal activity that lead to violence at older teen ages. However, the age group 13-15 is actually the MOST likely age group to be victimized by a child abduction/murderer, with 28% of victims in this age range (compare to 21% age 16-17, 21% children age 10-12, 21% children age 6-9, and 9% age 0-5). (Stats again from the "Investigative Management" cited above.)
The study you cited about the use of guns as weapons is looking specifically at the patterns of weapon use in sexual homicide offenders (
SAGE Journals: Your gateway to world-class research journals ). I think
@K.jill's original question was, are males or females more likely to use guns? Who is likely to use a knife? Your answer is not wrong but is limited to what male and female
sexual homicide offenders do, not all murderers or all child/teen murderers. So male sexual homicide offenders are more likely to kill victims by personal agency (strangling, beating), female sexual homicide offenders (of which there are very few) are more likely to use guns. This may or may not be informative per Delphi or any other case for which the motive has not been confirmed by LE. It likely will predict the cause of death in the Delphi case IMO as I believe that this, like most other child abduction/murders, was sexually motivated; but may not predict the cause of death in any other case
@K.jill might have in mind.
