Best evidence for left/right/mixed-handedness

[Pierre]

Hi Pierre

The best evidence for a left-handed or right-handed (or even ambidextrous or mixed-handed) killer is in the case of Alice McKenzie. Determining which of the Whitechapel Murders was committed by Jack the Ripper is another thing, but Dr Phillips noted that five small bruises on the side of McKenzie`s abdomen could have been made by the killers right hand (the size of the bruises indicating which was the little finger and which was the thumb, and therefore the right hand). Concluding that this left the killer`s left hand free to wield the knife.
Dr Bond did disagree, but he saw only saw the body the day after the post mortem, when the body had begun to decompose.

But from a layman`s point of view (me), a throat that has been cut left to right whilst the victim was on her back has to be by a right handed person.

.

OK, well I can not interpret these data at all right now. But it would be interesting, at least for me, to do some sort of analysis of the statements about left/right-handedness of the killer.

I think the difference in the statements are not due to post mortem examinators having differing points of views, but they can be explained by something else.

Regards, Pierre

[Jon Guy]

[B]Hi,

There have been various discussions about whether Jack the Ripper was left-handed or right-handed or even ambidextrous or mixed-handed.

What is the best evidence for any of these types, do you think?

And what do you think is the strongest evidence against any or some of them?

Hi Pierre

The best evidence for a left-handed or right-handed (or even ambidextrous or mixed-handed) killer is in the case of Alice McKenzie. Determining which of the Whitechapel Murders was committed by Jack the Ripper is another thing, but Dr Phillips noted that five small bruises on the side of McKenzie`s abdomen could have been made by the killers right hand (the size of the bruises indicating which was the little finger and which was the thumb, and therefore the right hand). Concluding that this left the killer`s left hand free to wield the knife.
Dr Bond did disagree, but he saw only saw the body the day after the post mortem, when the body had begun to decompose.

But from a layman`s point of view (me), a throat that has been cut left to right whilst the victim was on her back has to be by a right handed person.

.

[Robert St Devil]

Hello CertainSum1.

Errata,s use of the word ,,fine,, is accurate in these terms since which hand was used seems to fiane a detail to be relevant to the overall case. My primary interest is the following: an alternative to an ambidextrous solution is the involvement of more than one person.

[CertainSum1]

Has handedness as forensic evidence been backed up by data? Meaning have forensics smarty pants determined that the killers suspected to be lefties or righties were proven to be so? (Kind of the way blood spatter evidence is confirmed to be forensically sound?)

[Errata]

Hello all.

I,m certain that we could determine his ,handedness, based on how he tied the knot on the ligature for each of these women. I,m trying to recall other aspects that could offer insight beyond the victim particulars - what hand he carried the parcel in, what hand he carried his bag with, is there anything about how he wears/uses a pocketwatch, do the words in the suspected letters suggest right or left based on handwriting.

Truthfully, handedness is typically only remotely useful in finding killers who beat their victims to death. It's the one skill outside writing or fine tasks like threading a needle, where a person really does have a dominant hand. And the pattern of bruising will show that pattern. So if a lefty beat someone to death, that he was a lefty is important. If he shot a guy, it's clearly not useful information, even if you get it.

Cutting a throat seems like a fine task, but it's really not. It is most assuredly a strength task, and the strength of hands is too varied between people to be useful. My strength hand is my left. My husband's is his right. We are both right handed. The finest task the Ripper performed was cutting through the pericardium to reach the heart. And that probably required his dominant hand. But nothing else did. Which might be why the doctors couldn't agree. Likely he was switching hands to get a particular angle, or make the strongest cut, or even to avoid barking his knuckles against the ground. When you cut stuff you move around, you switch hands. Clean a leg of lamb sometime and see how often you contort, shift, and change hands. It's no different on a human. Doc sees right handed cuts because they were probably right handed cuts. Another sees left handed orientation because it was left handed orientation. It's not ambidexterity because it's not a matter of dexterity. It's just run of the mill mixed handedness.

So what does it matter if the killer was left handed? It's not rare enough to really narrow down the suspect pool. It might clear someone. Maybe. Also, he may write with his left hand but cut with his right. I do. Different skills being used. So someone looking for a left handed cutter is going to blow past me if he is looking at the hand I write with. And he shouldn't. A big thing is made about the handedness of a killer, like it's significant. It almost never is. Anyone know whether Dahmer was left or right handed? Did it matter in the slightest?

[Robert St Devil]

Hello all.

I,m certain that we could determine his ,handedness, based on how he tied the knot on the ligature for each of these women. I,m trying to recall other aspects that could offer insight beyond the victim particulars - what hand he carried the parcel in, what hand he carried his bag with, is there anything about how he wears/uses a pocketwatch, do the words in the suspected letters suggest right or left based on handwriting.

[John G]

19?

Regards, Pierre

Well spotted Pierre! Of course, I meant Post 10-not sure where 19 came from! I have now corrected my inaccurate post.

[Pierre]

Erm...my I respectfully suggest you read posts 3 and 19 of this thread?

19?

Regards, Pierre

[John G]

The physical setup within room 13 and the initial attack evidence would seem to indicate a left handed killer. None of the other murders have such evidence available. Ambidexterous people are 1% of any population, so 1 killer of Five, an ambi-killer, is highly unlikely.

Erm...my I respectfully suggest you read posts 3 and 10 of this thread?

[Pierre]

All of this is assuming that knife killing someone is not necessarily a multi handed affair. Handedness doesn't matter with tasks that routinely require both hands to be used either alternately or as needs must. And using a knife for any extended period of time is not particular a fine task, does not particularly require the use of the dominant hand, and is frankly tiring and awkward enough to require switching hands at regular intervals. This is notcalligraphy. He used both hands, sometimes both at once. Does that make him ambidextrous? No. It would if he could write calligraphy with both hands. Murder is not so fine a task.

And perhaps we should be more worried about the different statements of doctors on the subject. Why are there different opinions? And is there any type(s) of pattern(s) as to the differences?

Regards, Pierre

[Errata]

All of this is assuming that knife killing someone is not necessarily a multi handed affair. Handedness doesn't matter with tasks that routinely require both hands to be used either alternately or as needs must. And using a knife for any extended period of time is not particular a fine task, does not particularly require the use of the dominant hand, and is frankly tiring and awkward enough to require switching hands at regular intervals. This is notcalligraphy. He used both hands, sometimes both at once. Does that make him ambidextrous? No. It would if he could write calligraphy with both hands. Murder is not so fine a task.

[Michael W Richards]

Hi,

There have been various discussions about whether Jack the Ripper was left-handed or right-handed or even ambidextrous or mixed-handed.

What is the best evidence for any of these types, do you think?

And what do you think is the strongest evidence against any or some of them?

Regards, Pierre

The physical setup within room 13 and the initial attack evidence would seem to indicate a left handed killer. None of the other murders have such evidence available. Ambidexterous people are 1% of any population, so 1 killer of Five, an ambi-killer, is highly unlikely.

[Kattrup]

I think the best evidence for a right-handed killer is:

descriptions of the crime scenes and the positioning of the victims.

These, to me, imply a right-handed killer.

By this I mean for instance Stride, found facing the wall, close to the wall, which would make it harder for a left-handed man to squat and cut her throat.

Or Eddowes' intestines being placed over by her right shoulder, her right leg drawn up - this suggests to me a right-handed killer, kneeling at her right side. As he cuts things out, he places them to his left (her right shoulder) to clear his workspace. Cause of death from bleeding out the left carotid artery, again something that would be less likely if the killer was left-handed.

Chapman also had two separate cuts on the left side of her neck, I believe.
Nicholls too had a separate 4-inch cut from her left ear to below the jaw. A more difficult cut for a left-handed killer.

All this presumes the victims were unconscious and lying down more or less as found when they were killed, but I think the evidence supports that (no struggle, signs of strangulation).

The Kelly crime scene photo to me also suggests a right-handed killer; with the bed against the wall a left-handed killer would have been hampered. MJK being placed so close against the headboard means the killer was between her legs and/or on her left side.

While not evidence, I think it's relevant that the vast majority of the population is right-handed, thus, there's no need to look for the unusual, unless there's reason to do so. I don't think there is.

[Trevor Marriott]

Hi Trevor,

I have been looking for relevant forensic research (academic research) about this issue. It is impossible to find any substantial research.

Has Biggs done any research on it?

Regards, Pierre

Dr Biggs is a forensic pathologist. He speaks from knowledge and experience in assisting in the investigation of murders etc.

https://www.trevormarriott.co.uk

[Pierre]

I asked Dr Biggs detailed questions about this issue here is his reply

"It is really impossible to say with certainty how the wounds were inflicted in terms of ‘reconstructing’ events from the appearance of wounds. This is something that used to be quite ‘popular’ even up until relatively late on in the 20th century, with pathologists stating confidently that a left-handed dwarf with a limp inflicted the injury from behind using a specific knife, etc. Nowadays it is accepted that there is so much variation that in such cases, apart from a few ‘extreme’ scenarios that can be more-or-less excluded, just about anything is possible.

So in other words, the killer could have been behind the victim (with them both standing), or he (or she!) could have been ‘above’ the victim (kneeling, squatting, crouched, lying, stooping…) whilst she lay upon the ground (+/- prior strangling). Or it could have happened during a highly dynamic struggle, with all manners of grappling, twisting and fortuitous slashing going on. Only persons present at the time really know what went on (and we can’t ask them!), and nobody can be certain about a ‘reconstruction’ now based on photos / medical records"

If a number of envisaged scenarios are actually ‘possible’, then nobody can really argue in favour of a particular one any more than another.

www.trevormarriott.co.uk

Hi Trevor,

I have been looking for relevant forensic research (academic research) about this issue. It is impossible to find any substantial research.

Has Biggs done any research on it?

Regards, Pierre