Just to clear the air a bit, there is a very distinct difference between "Lust murder" and sadism
Each of these have a specific criteria to make that determination, however I haven't read anywhere where these were present at this scene.
Though both of these are a result of a paraphilia's they both have distinct behavioral differences.
Ill refrain from going into the specifics, but I don't feel this was a lust murder, and there's no evidence mentioned to support sadism (torture etc..)
Ok as always Profile the victim through a victimology analysis
(I wont post it again, because its so damn large, unless someone wants me to)
But establish why she was a victim, establish her risk criteria, establish the risk criteria for the offender.
Scrutinize, who she hung around with, look at her phone records, who did she talk to , who visited recently .
Did something happen recently?
Was she being stalked by anyone ?
It would be IMPERATIVE to establish if the murder weapon came from the residence, or if it was brought by the killer, from what I read the weapon was both brought and removed.
we can also look for POST offensive behavior, did any of her friends, all the sudden and unexplainably move ?, anyone notice any of her friends, have an sudden increase, in alcohol or drug use?, anyone change their appearance?
Though the victim was killed, we have to ask the question, is this more of a rape, gone wrong, or a planned murder with a sexual element?
Being since the sexual assault appears to be ante-mortem (before death) we can make a scientific assumption the motive for this crime was rape with murder secondary
Rape generally falls into 3 categories, (Power/Anger/Opportunity) with 4 subcategories that make up the first 2 typologies .
I use these typologies, because the offender, was organized enough to bring a weapon , or had it on his person in the first place
1) Power (most common) 2 types (Reassurance/Assertive)
2) Anger (less common) 2 types (Retaliatory/Excitation)
3) Opportunistic -Rape during the commission of another crime, (Ex burglary)
There's no mention of her being robbed, or anything taken from the victim or her apt, I also didn't read anywhere that the victim was bound or restrained, in any way , so opportunistic rape tentatively can be set aside.
Anger Retaliatory types, (as well as Sadists) usually attack strangers, id expect to see various forms of humiliation, these are individuals "haters" if you will , of something real or perceived. they feel an injustice has been laid upon them and they seek to make the victim pay (whether it be direct, indirect, or reflective) wrongs.
Often injuries targeted at sexual organs , usually severe depersonalization, humiliation, scripting (forcing the victim to say or act a certain way) are present . The victim often suffers more blunt trauma, than is needed to force victim compliance.
The problem is that this is usually not planned, and is most often a type of spontaneous response, to some triggering event. Hence the offender most often DOESNT bring a weapon. He usually relies, on his fists, or what he can access readily at the crime scene.
There's no evidence of torture, or prolonged, suffering by the victim, PLUS, Sadists (anger excitation) rapists, don't generally assault those they know, about 90% percent are strangers. Not to mention they are the least common typology (2%). Sadism usually requires time with the victim, for without the stimulation of an suffering victim, the offender, cannot begin toe arousal or gratification process. "Its always by way of pain, one arrives at pleasure "..Marquis De Sade
The Power reassurance rapist (the most common type) or "gentleman rapist" is basically someone who seeks to reaffirm their masculinity, through the process of rape. He often rapes strangers whom he tries (though it will sound odd) to connect to intimately. He will often caress the victim, kiss the victim, talk to the victim the way a significant other would. He has NO intention of physically injuring the victim, unless its what's needed to force victim compliance, which can has included violence up to and including murder in rare cases. .
He may conduct surveillance, on the victim prior , and most often uses, a surprise style of attack, though he may attempt to do so through con or ruse.
He's often apologetic following the rape, sometimes before or during, often suffers from some type of sexual dysfunction , may or may not take a trophy.
This type will often re-contact victims, through the delusion the victim actually enjoyed the assault , and may wish to pursue a relationship with the offender.
Though we can speculate that the victim resistance to the attack MAY have been the catalyst for her murder, I find that difficult to say, due to the amount of overkill (50+ stab wounds) and the fact the offender brought and removed the weapon
That leaves one type, Power Assertive rape.
The power assertive type is the second most common type of rapist .
The Power assertive, is basically your "macho" type, who feels its his right as male to take sexually that which he desires.
Date rape is not beyond his realm of behavior
Will often use enough force to force victim compliance, but will escalate along with victim resistance, (he cant let a victim, especially a female, physically or mentally dominate him)
Often meets the victim immediately prior to the attack, could be hours, or even minutes.
Demonstrates little concern for the victim, often callous indifference , will often cut (if he brought a weapon) or tear her clothes off.
Psychologically women are a means of gratification (sexual release) that's it, to him its his unwritten right as a male. Therefore he may frequent singles bars, singles events, dating sites, may frequent prostitutes, even though he may be in a relationship
If he is in a relationship, it will be one of mostly dominance by him with a somewhat submissive partner, whom he may be significantly older than.
May or may not bring a weapon, if he does its usually a weapon of choice, (knife or gun most often)
May commit multiple assaults within a small timeframe
(investigative consideration, check to see if there were any other assaults bearing this type of behavior in the hours, or days following her murder!)
he often knows his victim... which is what we all seem to identify with on this case. We know she resisted , at least verbally, which to the above type individual could trigger, an escalation of force, needed.. It may have also been a way to eliminate a witness, if he felt threatened she would call police post offense.
Though my feeling is she fought him, and he escalated, to the point he was going to "show her"
This all seems to exist in this case within a interpersonal realm with the offender and victim (She knew him)