Monday, 19 June 2017

“Backspatter” and Malcolm Fletcher’s explanation for blood inside the silencer.

Today I would like to talk about the evidence relied upon at my trial regarding the issue of back spatter. Malcolm Fletcher was the prosecution ballistics expert who worked at Huntingdon Laboratory and forensically examined firearms exhibits related to my case. At my trial, Fletcher described to the court that, in his opinion Sheila’s blood entered the silencer from the contact wound to her neck through the process he referred to as 'back spatter'[i]. This, he concluded, led him to believe that the silencer was attached to the .22 rifle when Sheila received her wounds[ii].

During his testimony regarding this central issue, Malcolm Fletcher quoted from an article to support his argument, which was written by American scientists Stephens and Allen called ‘Backspatter of Blood’ written in 1982[iii]. These two scientists had not carried out their own experiments but simply quoted the results of those done by another scientist Dr Herbert Leon MacDonnell the founder of the Bloodstain Evidence Institute in America.[iv] However the experiments conducted in 1971 were not done using a .22 calibre rifle but a .38 revolver.

At my trial Fletcher gave testimony that he had never personally observed the phenomenon of backspatter, and that no one had ever observed backspatter of blood in a .22 calibre weapon, the calibre of the rifle used in the incident at White House Farm on 7th August 1985[v]. Fletcher also admitted he had not conducted any experiments to establish the possibility of backspatter, claiming that he had neither the facilities nor the equipment to conduct such tests, and when asked how much a silencer would reduce the emission pressures which were essential for backspatter to occur he informed the court that he had “No idea”[vi]. However, by its very nature the whole concept of a silencer is to significantly reduce the pressure and the velocity of gas which emerges from the muzzle.

In their article Stephens and Allen record that according to some experts backspatter of blood from gunshot wounds does not exist[vii]. They state a number of times that back spatter cannot be achieved from a fleshy part of the body and it appears that Malcolm Fletcher misinterpreted their comments. They wrote[viii]:
  • In our experience backwards spatter of blood occurs most commonly in association with contact gunshot wounds of the head. 
  • Back spatter rarely occurs in gunshot wounds of the abdomen and chest. 
  • Back spatter is not typically associated with wounds in which there is a potential space immediately underlying the entrance site. 
  • The accelerating force is the backwards stream of escaping gas trapped between the elastic skin and rigid skull. 

In the case of Sheila Caffell her two gunshot wounds were located in soft flesh directly below her chin on her neck. There is no hard surface beneath the wounds to support the expanding gas and therefore nothing to create back spatter[ix]. The trial jury had no other evidence put before them to account for how such a large quantity of blood came to be inside the silencer down to perhaps the 6th or 7th baffle plates[x]. Fletcher did however state that someone could have dripped the blood into the silencer as he informed the judge when asked how else blood could have entered the silencer to account for the quantity of blood found inside it: “There is only one I can think of and that somebody deliberately taking blood with a pipette and dripping it very carefully inside.[xi]

It has recently come to my attention that Dr Herbert Leon MacDonnell’s forensic work on which Fletcher based his testimony is now seriously undermined following his conviction for child sex offences in 2013. It is recorded that MacDonnell used his professional influence to prevent detection of these serious crimes and therefore the integrity of his research is certainly brought into question[xii].


[i] AH-06-08) Malcolm Fletcher (Transcript) PDF Page 78 at G and H and 79 at A

[ii] AH-06-08) Malcolm Fletcher (Transcript) PDF Page 102 at A

[iii] AH-06-08) Malcolm Fletcher (Transcript) PDF Page 102 at B, C and D and AH-06-08) Malcolm Fletcher (Transcript). PDF, Pg. 102 at C: “There is an article actually which I have a copy of from one of the journals”.

[iv] Legal Medicine Annual Appleton Century Crofts, New York 1971 PP 89-136) published in 1971.

[v] AH-06-08) Malcolm Fletcher (Transcript) PDF Page 104 at F: “Q. .22 back spattering, with a moderator, when have you seen that? A. I can’t recall having seen one before today.”

[vi] AH-06-08) Malcolm Fletcher (Transcript). PDF, Pg. 104 at B, C, D, E, F, G, H and page 105 at A: “How much is the emission pressure reduced by the moderator? A. I have no idea Q) Have you tested it? A) I don’t have the equipment and facilities to do that

Q) Have you sought others to test it for you? A) No Sir. Q) It is rather important isn’t it? A) You obviously consider it so (rather impertinent) Q) The .22 is the least likely candidate for a gun to produce back-spattering?

A) Yes Sir Q) And a moderator would make it more unlikely, make it less likely? A) Slightly less likely Q) To an extent which you have not tested? A) Correct. Q) Nor experienced? A) Nor experienced.”

[vii] Technical Note Stephens and Allen PDF Page 1 paragraph 1

[viii] Technical Note Stephens and Allen PDF.

[ix] This is supported by e mail correspondence with Expert Ballistics witness John Bloomfield dated 24.04.17.

[x] AH-06-08) Malcolm Fletcher (Transcript) PDF Page 108 at F

[xi] AH-06-08) Malcolm Fletcher (Transcript) PDF Page 122 at G; “There is only one that I can think of and that is somebody deliberately taking blood with a pipette and dripping it very carefully inside.”

[xii] Forensic Fraud Article MacDonnell dated 07.07.13

Jeremy Bamber

Jeremy Bamber
Innocent Jeremy Bamber