Author Topic: About drawback or backspatter.  (Read 91470 times)

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Offline Holly Goodhead

Re: About drawback or backspatter.
« Reply #15 on: February 25, 2015, 06:00:02 PM »
Further to my link above and as follows:

http://www.finalanalysisforensics.com/media/pdfs/BasicBloodstainPatternAnalysisTEXT.pdf

Page 6:

"3. Draw-back effect
a) The draw-back effect sucks blood into the muzzle of a firearm
immediately after its discharge due to the partial vacuum created by
contracting discharge gasses.
b) The draw-back effect can be observed in contact gunshot wounds but
the effect(s) of compensators, suppressors and silencing devices as
well as any other intervening items may alter the outcome".


 &%+((£
Just my opinion of course but Jeremy Bamber is innocent and a couple from UK, unknown to T9, abducted Madeleine McCann - motive unknown.  Was J J murdered as a result of identifying as a goth?

Offline Myster

Re: About drawback or backspatter.
« Reply #16 on: February 25, 2015, 06:18:47 PM »
According to that last vague statement it's just as likely that more blood may be drawn back into a moderator than less or none at all.

So I think we're all agreed that the blood in the Anschutz moderator got there as a result of drawback, rather than through any deliberate attempt by police or anyone in the family to tamper with the evidence.

Here endeth the lesson.  8((()*/
It's one of them cases, in'it... one of them f*ckin' cases.

Offline Holly Goodhead

Re: About drawback or backspatter.
« Reply #17 on: February 25, 2015, 07:59:07 PM »
According to that last vague statement it's just as likely that more blood may be drawn back into a moderator than less or none at all.

So I think we're all agreed that the blood in the Anschutz moderator got there as a result of drawback, rather than through any deliberate attempt by police or anyone in the family to tamper with the evidence.

Here endeth the lesson.  8((()*/

A resounding NO from me! 

I agree the link above is ambiguous and could mean more or less likely.  Regardless I still think the whole phenomenon of draw back is rare and requires all the conditions to be A1: calibre of weapon, bullet size, contact wound, anatomical location, angle.  As far as I can see the conditions at WHF were anything but A1.  There's also the question of how far the blood could travel, distribution ie flake, and lack of accompanying biological material eg skin tissue, bone fragments. 

Am I right in saying that Herb McDonnell evaluated WHF and came to the conclusion that JB was the likely perp, but at this stage he was unaware that a silencer had been used?  When he found out a silencer had been used he said he would need to re-evaluate but that never happened as JB run out of funds?  JB funded the initial evaluation from payment from Wilkes (book) for his input?   
Just my opinion of course but Jeremy Bamber is innocent and a couple from UK, unknown to T9, abducted Madeleine McCann - motive unknown.  Was J J murdered as a result of identifying as a goth?

Offline Myster

Re: About drawback or backspatter.
« Reply #18 on: February 25, 2015, 08:59:17 PM »
A resounding NO from me! 

I agree the link above is ambiguous and could mean more or less likely.  Regardless I still think the whole phenomenon of draw back is rare and requires all the conditions to be A1: calibre of weapon, bullet size, contact wound, anatomical location, angle.  As far as I can see the conditions at WHF were anything but A1.  There's also the question of how far the blood could travel, distribution ie flake, and lack of accompanying biological material eg skin tissue, bone fragments. 

Am I right in saying that Herb McDonnell evaluated WHF and came to the conclusion that JB was the likely perp, but at this stage he was unaware that a silencer had been used?  When he found out a silencer had been used he said he would need to re-evaluate but that never happened as JB run out of funds?  JB funded the initial evaluation from payment from Wilkes (book) for his input?
MacDonnell knew about the moderator, but through a misunderstanding in communication thought that it was attached to another rifle.  His other general remarks about the bible, blood flow and trails still stand as sound reasoning that Sheila didn't kill herself.

I suggest we apply for a firearm's licence, all chip in to buy an '85 vintage Anschutz 525 + Parker-Hale moderator, and experiment on something living... so you'll be fully satisfied that drawback (and backspatter) does occur at close range.

... or maybe not, because then you'll get a bee in your apostolnik about something else.

http://watchingyouwatchingyme-steelmagnolia.blogspot.co.uk/2011/02/bamber-report-from-prof-herbert-leon.html
It's one of them cases, in'it... one of them f*ckin' cases.

Offline Holly Goodhead

Re: About drawback or backspatter.
« Reply #19 on: February 26, 2015, 12:25:38 AM »
MacDonnell knew about the moderator, but through a misunderstanding in communication thought that it was attached to another rifle.  His other general remarks about the bible, blood flow and trails still stand as sound reasoning that Sheila didn't kill herself.

I suggest we apply for a firearm's licence, all chip in to buy an '85 vintage Anschutz 525 + Parker-Hale moderator, and experiment on something living... so you'll be fully satisfied that drawback (and backspatter) does occur at close range.

... or maybe not, because then you'll get a bee in your apostolnik about something else.

http://watchingyouwatchingyme-steelmagnolia.blogspot.co.uk/2011/02/bamber-report-from-prof-herbert-leon.html

The fact there was a misunderstanding in communication and MacDonell made his assessments based on the wrong firearm does not fill me with confidence.  In effect the whole thing can be written off.  With regard to the aspects he reviewed that were not connected to the firearm he hasn't taken into account that it's pretty much a racing cert EP moved SC, the rifle and bible before photos were taken.  It was some 2.5 years ago when I read Wilkes book but I think I recall MacDonell's report was some sort of budget version and the real McCoy was going to involve some significant outlay.  To my mind it seems strange that JB would commission a world renowned expert such as MacDonell knowing he was guilty?

I have for the first time Googled various permutations of 'draw-back' and 'drawback' along with other relevant words eg firearms, gunshot, etc and there's very little info.  This seems to support my claim that the phenomenon of blood being sucked back into a firearm with or without a silencer is rare.

Blood pattern analysis seems an important consideration and yet in the CoA document we are told there was a considerable amount of blood and a flake:

76. Inside the moderator, on the four or five baffles nearest to the end from which the bullet would exit, there was a considerable amount of blood. At one point blood had pooled to form a flake when it dried, and this flake was subjected to group testing. Results were obtained for four of the five tests performed. Mr Hayward, the forensic scientist said that they showed that the blood could have come from Sheila Caffell but not from any of the other individuals involved. Mr. Hayward said that there was a possibility that the blood could be a mixture of blood from more than one person and if it was, a mixture of blood from Nevill Bamber and June Bamber could account for the findings in the grouping tests. However he judged that possibility to be a "remote" one.

It sounds a bit basic?

MacDonell has stated that draw-back with a .22 could travel as far back as 2.53 cm to 3.8cm.   The length of the Parker Hale silencer is 17.3cm.  The blood was found as far back as the 5th baffle so does this take it beyond the 3.8 cm?  How far back is the 5th baffle?  It appears there are 15 baffles with a Parker Hale so assuming they are evenly spaced and allowing a bit extra either end it sounds to me although 5 baffles in would take it beyond 3.8cm?   ?>)()<

"Results obtained from the research of MacDonnell and Brooks revealed that
penetration depth of small calibre weapons like .22 calibre revolvers, ranged from 1 to
1,5 inches (2,53 to 3,8 cm). The depth of detectable blood droplets in higher calibre guns
such as 12-, 16-, or 20-gauge shotguns reached up to 5 inches (12,65 cm) and for
handguns approximately 3 inches (7,6 cm)"

Also as the draw-back phenomenon is based on suction not only is blood drawn back into the silencer but also other biological material but none were present:

"The drawback effect (or blowback effect) is a phenomenon seen mainly in contact
and close-range gunshot wounds. It refers to the process in which blood droplets are
deposited inside the barrel of a weapon after discharge. The cause of this phenomenon
has not yet been agreed to, but current theories include the increased pressure in the
gunshot wound and the near vacuum in the barrel (created by the discharged gases
escaping along with the projectile), which then creates a sucking effect that sucks blood
and other biological tissue into the barrel".




Just my opinion of course but Jeremy Bamber is innocent and a couple from UK, unknown to T9, abducted Madeleine McCann - motive unknown.  Was J J murdered as a result of identifying as a goth?

Offline Holly Goodhead

Re: About drawback or backspatter.
« Reply #20 on: February 26, 2015, 01:16:48 AM »
I see from this vid previously posted by Myster that one third of the silencer (open end away from barrel) is in fact referred to as a gas chamber and contains no baffles.  The baffles sit behind this.  Therefore 5 baffles in takes the blood found in the silencer well beyond MacDonell's claim of up to 3.8 cm!?

https://m.youtube.com/watch?v=aGrGCnStmrk


 ?>)()<
Just my opinion of course but Jeremy Bamber is innocent and a couple from UK, unknown to T9, abducted Madeleine McCann - motive unknown.  Was J J murdered as a result of identifying as a goth?

Offline Holly Goodhead

Re: About drawback or backspatter.
« Reply #21 on: February 26, 2015, 01:37:07 AM »
Actually I think I've got it the wrong way round  @)(++(* The baffles are nearer the end away from the barrel which would probably mean the 5th baffle is within the 3.8cm.  But effectively the baffles reduce the aperture so surely the distance the blood could travel as a result of draw-back would be reduced?  With larger calibre weapons the blood is capable of travelling further ie being drawn back further? 

There's a dearth of info re draw-back with a silencer. 
Just my opinion of course but Jeremy Bamber is innocent and a couple from UK, unknown to T9, abducted Madeleine McCann - motive unknown.  Was J J murdered as a result of identifying as a goth?

Offline scipio_usmc

Re: About drawback or backspatter.
« Reply #22 on: February 26, 2015, 02:29:59 AM »
According to that last vague statement it's just as likely that more blood may be drawn back into a moderator than less or none at all.

So I think we're all agreed that the blood in the Anschutz moderator got there as a result of drawback, rather than through any deliberate attempt by police or anyone in the family to tamper with the evidence.

Here endeth the lesson.  8((()*/

The vague statement that it MAY alter the outcome doesn't mean there will be no drawback at all.  You have to look at the individual characteristics of the of the wounds and the characteristics of the device being used.  Her source in the meantime is only discussing drawback that results from gases.  Note that there are 3 different things that cause drawback that is why I posted the source I did.  Holly just surfs fo rthings that she thinks supports her claims without actually looking for things that are accurate and discuss everything in full.

Holly needs to find a source that says baffled moderators liek the one in question prevents drawback no matter where on the body a contact wound is received from a wepaon fitted with such moderator.  That of course she won't find because blood is routinly found in moderators when used at contact range. 

Some suppressors have jagged edges that allow alot of gases to escape before reaching the body.  Some even have holes that vents that allow gases to escape out of the sides.  The moderator is question has neither vents nor is the tip jagged.   

The firearm experts in this case and medical experts examined the exact wound location to determrine it would result in drawback and the exact moderator for the proposition it would result in drawback.  Holly wants to ignroe the specifics and try finding generalize claims that she can try to twist to support her agenda.  That doesn't work.

She needs to get a medical expert to assess the specific wound location based on the exact circumstances of this case.

“...there are three classes of intellects: one which comprehends by itself; another which appreciates what others comprehend; and a third which neither comprehends by itself nor by the showing of others; the first is the most excellent, the second is good, the third is useless.”  Niccolò Machiavelli

Offline scipio_usmc

Re: About drawback or backspatter.
« Reply #23 on: February 26, 2015, 04:29:48 AM »
Actually I think I've got it the wrong way round  @)(++(* The baffles are nearer the end away from the barrel which would probably mean the 5th baffle is within the 3.8cm.  But effectively the baffles reduce the aperture so surely the distance the blood could travel as a result of draw-back would be reduced?  With larger calibre weapons the blood is capable of travelling further ie being drawn back further? 

There's a dearth of info re draw-back with a silencer.

In general the larger the caliber the further the blood with be able to travel but the velocity of the rounds and other properties of the rounds also plays a role. Further means instead of the maximum travel distance being a few inches it can be 5 or 6. 45 caliber bullets by way of example are quite slow compared to most bullets out so different rules apply, there are always exceptions.  This general rule applies to back spatter that flies outside a weapon as well as to drawback.  Blood could travel several feet more outside the gun and several inches more inside a gun if a larger caliber projectile as opposed to a small caliber.  So while it will travel maybe 4 inches deep for a 22 it can end up 6-8 inches for larger projectiles. Only the smaller drops make it to the maximum distance though.  The larger drops have too much surface area so they don't go as far.  The larger drops are still small though. These are macro and micro sized drops, the macro travel further.  That is one reason why you see the volume heaviest towards the end and getting lighter deeper inside.   

Generalizations only work to a limited extend since location of the body is such an important factor.
“...there are three classes of intellects: one which comprehends by itself; another which appreciates what others comprehend; and a third which neither comprehends by itself nor by the showing of others; the first is the most excellent, the second is good, the third is useless.”  Niccolò Machiavelli

Offline Holly Goodhead

Re: About drawback or backspatter.
« Reply #24 on: February 26, 2015, 01:31:03 PM »
In general the larger the caliber the further the blood with be able to travel but the velocity of the rounds and other properties of the rounds also plays a role. Further means instead of the maximum travel distance being a few inches it can be 5 or 6. 45 caliber bullets by way of example are quite slow compared to most bullets out so different rules apply, there are always exceptions.  This general rule applies to back spatter that flies outside a weapon as well as to drawback.  Blood could travel several feet more outside the gun and several inches more inside a gun if a larger caliber projectile as opposed to a small caliber.  So while it will travel maybe 4 inches deep for a 22 it can end up 6-8 inches for larger projectiles. Only the smaller drops make it to the maximum distance though.  The larger drops have too much surface area so they don't go as far.  The larger drops are still small though. These are macro and micro sized drops, the macro travel further.  That is one reason why you see the volume heaviest towards the end and getting lighter deeper inside.   

Generalizations only work to a limited extend since location of the body is such an important factor.

Results from your frequently quoted source (MacDonnel) as follows:

"Results obtained from the research of MacDonnell and Brooks revealed that
penetration depth of small calibre weapons like .22 calibre revolvers, ranged from 1 to
1,5 inches (2,53 to 3,8 cm). The depth of detectable blood droplets in higher calibre guns
such as 12-, 16-, or 20-gauge shotguns reached up to 5 inches (12,65 cm) and for
handguns approximately 3 inches (7,6 cm)"

They (MacDonnel and Brooks) have not made mention of any variables.  Perhaps that's why they have stated 2.53cm to 3.8cm ie allowing for variations with bullets.

Your OP states 3cm with MacDonnel and Brooks being the source.

http://miscarriageofjustice.co/index.php?topic=6061.msg222006#msg222006

Calibre  (internal diameter of the barrel) is one determinant in how far blood can be drawn back into the barrel.  Therefore it seems to me that if a silencer is fitted this effectively reduces the internal diameter of the point the bullet exits and biological material can enter (see diagram below).  I am not saying that it is not possible but I am saying based on my interpretation of MacDonnel's research it seems to me the distance the biological material could travel back into the silencer due to the phenomenon of drawback would be significantly reduced? 

Since you are clearly an expert in all of this are you able to let us know the position of the 5th baffle in terms of its furthest point from the entrance of the barrel in mm's?

Perhaps this is what NGB was saying ie not that draw-back is not possible with a .22 but he thinks it doubtful with a silencer fitted? 

I have tried Googling all sorts of permutations with draw-back and drawback, silencers, moderators, suppressors, gunshot wounds and there's a dearth of info  &%+((£ 

If all this is as clear as mud then please share the links and research showing outcomes with silencers.

I'm finding this very baffling indeed  8)-)))


Just my opinion of course but Jeremy Bamber is innocent and a couple from UK, unknown to T9, abducted Madeleine McCann - motive unknown.  Was J J murdered as a result of identifying as a goth?

Offline Myster

Re: About drawback or backspatter.
« Reply #25 on: February 26, 2015, 07:34:28 PM »
Calibre  (internal diameter of the barrel) is one determinant in how far blood can be drawn back into the barrel. Therefore it seems to me that if a silencer is fitted this effectively reduces the internal diameter of the point the bullet exits and biological material can enter (see diagram below).  I am not saying that it is not possible but I am saying based on my interpretation of MacDonnel's research it seems to me the distance the biological material could travel back into the silencer due to the phenomenon of drawback would be significantly reduced? 
On the contrary, the calibre of the moderator should in theory be slightly be larger than that of the rifle to allow for any misalignment when the barrel is threaded and/or a coupling is attached, before the moderator is screwed on.  Otherwise when the bullet exits the rifle end and enters the moderator's expansion chamber it's liable to catch the baffles and knurled-end opening as it passes through them.  In fact the instruction sheet states that the thread at the muzzle end must be cut in accurate alignment with the rifle bore.  In the sectional drawing on the same sheet, look at the larger calibre of the moderator and coupling (right) in comparison to that of the rifle (left). 

Compare also the calibre of three different moderators for .22 rifles - the Parker-Hale in the middle of the first photo and on the left in the second, which shows it to be slightly larger than the others.  So even the narrower bore of the latter two must be capable of allowing the passage of a .22 bullet without hindrance.

That makes it more likely drawback blood (and possibly a small amount of backspatter) will enter the moderator end, not less.



Top to bottom - SAK, Parker-Hale, ASE Ultra.


Left to right - Parker-Hale, SAK, ASE Ultra.
« Last Edit: February 27, 2015, 08:36:21 AM by Myster »
It's one of them cases, in'it... one of them f*ckin' cases.

Offline scipio_usmc

Re: About drawback or backspatter.
« Reply #26 on: February 26, 2015, 10:28:23 PM »
Results from your frequently quoted source (MacDonnel) as follows:

If all this is as clear as mud then please share the links and research showing outcomes with silencers.

I'm finding this very baffling indeed  8)-)))

1) the depth quoted above is not entirely accurate it is taking distances at which they fired weapons and still found some blood 5mm inside and misrepresenting that distance as how far inside the blood was

2) Every case is different a general observation is a general observation it doesn't preclude variation so you have to be careful. There are drops that were found 7 inches of more in weapons by coroners BUT just a few drops at most that far and they will be small drops because larger ones can't travel that far.  The bulk of the blood will be less deep. Even with respect to the data on blood in general going only 5mm or less inside when the gun is 1-1.5 inches away there were a few drops that managed to make it 6 or 7mm inside. When there is a huge difference between what has been observed by coroners and in tests then there is an issue that needs to be addressed. That issue could be something happening experts didn't think about before or could be attributale to something different than drawback.  Obviously the blood on the side that screws into the rifle wasn't drawback for instance. Either the killer tranferred the blood from his hands or stick it in something bloody or it leaked from the rifle there. It could not have been from drawback.   

You want there to be set things that happen to a precise distance no matter what without variation.  There is no such thing.  There will always be some variation.  Even with 22 calibers a drop or 2 might get an inch further in one case than another despite the locations of a shot on one victim and another being almost the same.

Whether a particular location is likely to result in back spatter is first and foremost a factor of the location of the wound and the second most important factor is the properties of the bullet not just caliber of the bullet the various properties. Whether the blood that is projected back will hit the weapon/shooter or any will go inside the weapon is a factor of distance.  At contact and near contact ranges an additional factor comes into play- the gases that are expelled.  There already would be drawback in many circumstances without the gases but the gases make drawback even more likely- location of the shot is still a factor though.

So you have to look at the location of the wound like the experts in this case did and assess based on that location and the nature of the skin and the nature of the blood inside that area and the effects of all 3 causes for drawback mixing together what will happen.  The experts did this very detailed look.  You are not going to find any such detailed analysis of locations in ordinary literatire this is a very fact intensive inquiry.

You want Jeremy to be innocent so you can promote your agenda about mental problems and adoption etc.   So you want evidence that the blood can't have resulted from drawback.  you are not going to find it.  There is nothing saying that drawback can't occur from a shot fired with a moderator or a 22 shot to the neck. It will be a futile search.

The evidence in publications comes from past criminal cases/homicide investigations and testing.  There are cases where some blood made it deeper inside than it did in studies.  Studies are not on real people and thus while they get patterns down pretty good and often they come close to replicting what is found in the field they can't preduct everything to the letter and slight variations always happen evne in the field when circumstances are very close.     

You want a nice neat table like a multiplication table students use but there is no such thing. 
   
The ONLY way to establish drawback can't result from a wound is by having somone assess the gun was too far away from the wound or that the specific location is impossible to result in drawback because of the nature of the body there.  But there is always a possibility of a contact owund resulting in drawback, even though 22 calibers  usually don't result in drawback they occasionally have done so thus it is not impossible. 

So finding someone to say it is impossible is off the table unless you find someoen who says the gunshot was too far away.  You at best can find an expert to assess drawback in a particualr area is not that likely to happen. The defense thus needed to find someone who disagreed that it was virtually certain to result in drawback and needed to find an expert who would assess it was unlikely that a contact wound to her neck in that location would result in drawback.  The defense couldn't find any experts willing to assert that though. 

The answer is not going to be found in any publications about drawback the reaosn why ther eis a "dearth" of information is it is a very fact intensive inquiry, you need to get an expert in medicine who is an expert in drawback to assess the 3 causes of drawback my source mentioned and apply the princilpes to the exact nature of the body in that area to assess whether drawback would be likely to occur there.

I doubt you know anyone with such expertise who you can turn to for free and doubt you want to pay. The defense already wound have had an expert testify to that effect if they had found one so that should clue you in that you are wasting your time and need another avenue of approach.




“...there are three classes of intellects: one which comprehends by itself; another which appreciates what others comprehend; and a third which neither comprehends by itself nor by the showing of others; the first is the most excellent, the second is good, the third is useless.”  Niccolò Machiavelli

Offline Holly Goodhead

Re: About drawback or backspatter.
« Reply #27 on: February 27, 2015, 12:30:38 PM »
On the contrary, the calibre of the moderator should in theory be slightly be larger than that of the rifle to allow for any misalignment when the barrel is threaded and/or a coupling is attached, before the moderator is screwed on.  Otherwise when the bullet exits the rifle end and enters the moderator's expansion chamber it's liable to catch the baffles and knurled-end opening as it passes through them.  In fact the instruction sheet states that the thread at the muzzle end must be cut in accurate alignment with the rifle bore.  In the sectional drawing on the same sheet, look at the larger calibre of the moderator and coupling (right) in comparison to that of the rifle (left). 

Compare also the calibre of three different moderators for .22 rifles - the Parker-Hale in the middle of the first photo and on the left in the second, which shows it to be slightly larger than the others.  So even the narrower bore of the latter two must be capable of allowing the passage of a .22 bullet without hindrance.

That makes it more likely drawback blood (and possibly a small amount of backspatter) will enter the moderator end, not less.



Top to bottom - SAK, Parker-Hale, ASE Ultra.


Left to right - Parker-Hale, SAK, ASE Ultra.


Thanks for the info Myster.  My mistake I was under the impression that the silencer sits flush with the barrel of the gun and therefore the calibre of the silencer would be smaller.  However I can see this is not the case (image below).  In any event I wasn't saying that the silencer, and what I thought would be a smaller calibre, would rule out draw-back I was questioning the distance the blood travelled ie 5th baffle and the way it distributed ie a flake.

There clearly is a difference between the barrel of a rifle and a silencer. 
Just my opinion of course but Jeremy Bamber is innocent and a couple from UK, unknown to T9, abducted Madeleine McCann - motive unknown.  Was J J murdered as a result of identifying as a goth?

Offline Holly Goodhead

Re: About drawback or backspatter.
« Reply #28 on: February 27, 2015, 12:41:57 PM »
1) the depth quoted above is not entirely accurate it is taking distances at which they fired weapons and still found some blood 5mm inside and misrepresenting that distance as how far inside the blood was

2) Every case is different a general observation is a general observation it doesn't preclude variation so you have to be careful. There are drops that were found 7 inches of more in weapons by coroners BUT just a few drops at most that far and they will be small drops because larger ones can't travel that far.  The bulk of the blood will be less deep. Even with respect to the data on blood in general going only 5mm or less inside when the gun is 1-1.5 inches away there were a few drops that managed to make it 6 or 7mm inside. When there is a huge difference between what has been observed by coroners and in tests then there is an issue that needs to be addressed. That issue could be something happening experts didn't think about before or could be attributale to something different than drawback.  Obviously the blood on the side that screws into the rifle wasn't drawback for instance. Either the killer tranferred the blood from his hands or stick it in something bloody or it leaked from the rifle there. It could not have been from drawback.   

You want there to be set things that happen to a precise distance no matter what without variation.  There is no such thing.  There will always be some variation.  Even with 22 calibers a drop or 2 might get an inch further in one case than another despite the locations of a shot on one victim and another being almost the same.

Whether a particular location is likely to result in back spatter is first and foremost a factor of the location of the wound and the second most important factor is the properties of the bullet not just caliber of the bullet the various properties. Whether the blood that is projected back will hit the weapon/shooter or any will go inside the weapon is a factor of distance.  At contact and near contact ranges an additional factor comes into play- the gases that are expelled.  There already would be drawback in many circumstances without the gases but the gases make drawback even more likely- location of the shot is still a factor though.

So you have to look at the location of the wound like the experts in this case did and assess based on that location and the nature of the skin and the nature of the blood inside that area and the effects of all 3 causes for drawback mixing together what will happen.  The experts did this very detailed look.  You are not going to find any such detailed analysis of locations in ordinary literatire this is a very fact intensive inquiry.

You want Jeremy to be innocent so you can promote your agenda about mental problems and adoption etc.   So you want evidence that the blood can't have resulted from drawback.  you are not going to find it.  There is nothing saying that drawback can't occur from a shot fired with a moderator or a 22 shot to the neck. It will be a futile search.

The evidence in publications comes from past criminal cases/homicide investigations and testing.  There are cases where some blood made it deeper inside than it did in studies.  Studies are not on real people and thus while they get patterns down pretty good and often they come close to replicting what is found in the field they can't preduct everything to the letter and slight variations always happen evne in the field when circumstances are very close.     

You want a nice neat table like a multiplication table students use but there is no such thing. 
   
The ONLY way to establish drawback can't result from a wound is by having somone assess the gun was too far away from the wound or that the specific location is impossible to result in drawback because of the nature of the body there.  But there is always a possibility of a contact owund resulting in drawback, even though 22 calibers  usually don't result in drawback they occasionally have done so thus it is not impossible. 

So finding someone to say it is impossible is off the table unless you find someoen who says the gunshot was too far away.  You at best can find an expert to assess drawback in a particualr area is not that likely to happen. The defense thus needed to find someone who disagreed that it was virtually certain to result in drawback and needed to find an expert who would assess it was unlikely that a contact wound to her neck in that location would result in drawback.  The defense couldn't find any experts willing to assert that though. 

The answer is not going to be found in any publications about drawback the reaosn why ther eis a "dearth" of information is it is a very fact intensive inquiry, you need to get an expert in medicine who is an expert in drawback to assess the 3 causes of drawback my source mentioned and apply the princilpes to the exact nature of the body in that area to assess whether drawback would be likely to occur there.

I doubt you know anyone with such expertise who you can turn to for free and doubt you want to pay. The defense already wound have had an expert testify to that effect if they had found one so that should clue you in that you are wasting your time and need another avenue of approach.

The WHF tragedy is now almost 3 decades old.  The whole world has changed during this time.  Not least in the way we communicate.  The internet offers new opportunities to exchange information and identify and procure the very best expert witnesses from across the globe.

Imo JB's defence at trial was very poor.  The prosecution's firearms expert, Malcolm Fletcher, went largely unchallenged.  The defence was supported by Major Mead who, as I understand it, was not a firearms expert.  That was then and this is now.

I am particularly impressed with Dr Jon Nordby:

http://www.finalanalysisforensics.com/media/pdfs/Jon-Nordby-CV-140813.pdf

I like the way he communicates complex information:

http://www.finalanalysisforensics.com/media/pdfs/BasicBloodstainPatternAnalysisTEXT.pdf

Dr Jon Nordby tells us the following:

"3. Draw-back effect
a) The draw-back effect sucks blood into the muzzle of a firearm
immediately after its discharge due to the partial vacuum created by
contracting discharge gasses.
b) The draw-back effect can be observed in contact gunshot wounds but
the effect(s) of compensators, suppressors and silencing devices as
well as any other intervening items may alter the outcome".

The jury was not told that a silencer might alter the outcome of draw-back.  I am keen to understand how a silencer might alter the outcome of draw-back  &%+((£

Contrary to your assertion forensics are fully supported by established branches of science eg physics, maths, logic, biology, chemistry.  There is no doubt in my mind whatsoever that if the silencer was accidentally or deliberately contaminated that will now become apparent.  I would suggest sooner rather than later.  It is all to play for especially with regard to the distance the blood travelled ie the 5th baffle and the way in which it distributed ie a flake.  I believe this will tell us whether the blood was there as a result of a gunshot wound or not.

With regard to your interest in what motivates individuals to take an interest in the WHF tragedy/Jeremy Bamber's case have you ever considered your own motivations?   8(0(*
Just my opinion of course but Jeremy Bamber is innocent and a couple from UK, unknown to T9, abducted Madeleine McCann - motive unknown.  Was J J murdered as a result of identifying as a goth?

Offline Myster

Re: About drawback or backspatter.
« Reply #29 on: February 27, 2015, 05:18:38 PM »
Holly... where do you think that shootalike photo was taken?
It's one of them cases, in'it... one of them f*ckin' cases.