Thursday, 11 September 2014

Pistorius: witness evidence as to the charge of premeditated murder

It seems to me that the key issue in determining whether Oscar Pistorius should have been found guilty of premeditated murder is the interpretation of the witness evidence with regard to whether he and Reeva Steenkamp were arguing shortly before shots were fired.  I will give Pistorius the benefit of reasonable doubt in his favour in interpreting this "ear-witness" evidence, since that is what he is entitled to in law.  Clearly his actions in shooting into the bathroom without checking whether Steenkamp was in the bed make for bizarre conduct even on his own story.  It seems unlikely on the face of it, but let us check whether there is witness evidence to confirm the improbability of Pistorius' story or not.

Several witnesses testified about what they heard on the night of the tragic killing:
Michelle Burger.  She was living in the next housing estate from that of Pistorius, 177m away from his home.  According to Sky News' reporting, she was woken by "a terrible female scream" then heard "yells for help".  "She then heard a male voice calling for help three times."  She then "sat on her bed and heard further more intense screams" then "four gunshots".  She said: "After the shouts I heard screams. During the shots I heard her screaming and then it faded away. I did not note what shots, what screams I heard. Just a moment after the shots I heard the lady's screaming fade away."  She was asked: "If you say you heard a voice after the shots, what does it mean?"  To which she replied: "It means the voice that I awoke to [was the same person's voice]. She could have screamed with the last shot or shortly afterwards. I confirm that just after the last shot I heard her voice."  That is, "what I can say is that I heard the same woman's voice screaming as what woke me up that night."  She explained: "I heard a voice calling for help, I then heard a male voice screaming three times. I then made a call after that I heard her screaming. I then heard four shots. I did not hear her a minute after the last shot."  She claimed: "I am 100% certain that I heard a female and a male voice screaming."
Analysis: Burger says she heard a male voice calling for help before she heard gunshots.  If this is accurate, then it supports Pistorius' defence and contradicts the prosecution.  Pistorius' lawyer Barry Roux pointed out to Burger that Pistorius would not likely have called for help before deliberately murdering Steenkamp.  However, Burger also says that she was awoken by a female scream, which would suggest Steenkamp made that noise, perhaps during an argument with Pistorius, and either way he would have known where she was.  That supports the prosecution and contradicts the defence.  However, here is what the judge had to say on that point:
Casting doubt on witness accounts of hearing a woman's screams, Masipa said "none of the witnesses had ever heard the accused cry or scream, let alone when he was anxious," apparently acknowledging the defence argument that Pistorius had been screaming in a high-pitched voice.  Masipa also cited testimony of an acoustics expert called by the defence, saying it cast "serious doubt" on whether witnesses who were hundreds of metres away in their homes — as some state witnesses were — could have differentiated between the screams of a man or a woman.
If we accept the judge's scepticism as reasonable, then what remains of Burger's testimony favours the defence narrative that Pistorius fired into the door without imagining Steenkamp was inside the bathroom.
Estelle Van Der Merwe.  She was living in the same Silver Woods estate as Pistorius.  The reports record her saying: "I woke up around 1:56 in the morning. I heard sounds like someone was talking in loud voices. It lasted for about an hour. I couldn't hear what the person was saying. I also couldn't hear what language this person was speaking."  She says this was "the womans' voice".  She then heard four sounds like "bang, bang" then "no more voices".  Roux, for the defence, told her: "We did a test of a woman and a man screaming very loud in a bedroom at 2 - 3 in the morning. What's interesting, is that you could not have heard the screaming."
Analysis: clearly, if Van Der Merwe heard an hour of Pistorius and Steenkamp talking loudly leading up to the gunshots, then this supports the prosecution.
Charl Johnson, husband of Van Der Merve.  He said he "woke up after the first screams, when I heard the lady scream again I jumped up".  And: "I could hear she was in distressed and in trouble. I can't say exactly, at one point I heard her screaming help. Then at a stage I heard a male voice that shouted three times help, help, help."  Then, "the screaming was more intense.  I heard the first gunshot. During the shots I heard her screaming. The screams faded during the last shot."  He justified his discrimination of the female voice: "I am convinced that I heard a lady screaming. It was easy for me to distinguish because I heard a lady and a mans' voice."  He was also adamant that he heard gunshots, not the sound of Pistorius breaking the door in with a cricket bat: "I am certain it was gunshots."
Analysis: this was evidence flatly favourable to the prosecution: he ascribed screams for help to the female voice, in contrast to Michelle Burger.
Johan Stander, also of Silver Woods estates.  He said he "woke up to three loud bangs, that sounded like gunshots".  Then he heard "the woman screaming" then "more shooting".  After that, he heard "a man's voice screaming three times, HELP, HELP, HELP".
Analysis: this is curious.  Stander reports: gunshots, then screaming, then gunshots, then Pistorius calling for help. If the first series of gunshots killed Steenkamp, as we must suppose, since nobody is accusing Pistorius of firing two volleys separate in time, then this may be evidence that the sound of Pistorius screaming could be misheard as a female voice, and that the sound of the cricket bat striking the door could in fact be misheard as gunshots.  By contrast, the prosecution argued that, of the two sets of shots, only the second set were gunshots.  In that case, what were the first gunshots supposed to be?
The sound of female screaming after gunshots was also reported by Anette Stipp later in the trial.  "Stipp said she was on the balcony listening to the continuous female screams when she heard a man screaming at the same time. She couldn’t make out the words. Then she heard three more sounds like shots ... After the second group of shots, the screaming stopped."  "Anette Stipp told the court she heard two sets of three gunshots, however the prosecution and defense agree only four shots were fired. Throughout the trial, Pistorius' legal team has contended that a second set of bangs was Pistorius bashing down the toilet door with a cricket bat to get to Steenkamp."
Analysis: again, if the first gunshots killed Reeva, then the continuous female screams heard afterwards must have been Pistorius himself, and the second series of shots may have been the cricket bat against the door.  The defence's claims about Pistorius screaming so as to be misheard as a female voice, and the resemblance of the cricket bat's sound to gunshots seem to be confirmed.
Johan Stipp lived 72 metres from Pistorius.  He also described hearing female screaming after being woken by a sound of gunshots: "She sounded fearful. Of someone who was in fear of his or her life ... She sounded to be emotional, anguished, scared almost scared out of her mind, I would say."  He "heard the sound of a woman screaming and a male's voice".
Analysis: once again, who can be the female voice after the gunshots that woke Stipp up?
While trying to phone Silver Woods’s security back in his bedroom, [Stipp] heard three more bangs, which he thought were also shots and shouted for his wife to get to safety.
Analysis: and again, he heard bangs which sounded like gunshots, but which could not have been if the first series of sounds were indeed gunshots.  Once again, it sounds like the order of sounds heard was: gunshots, screams that sounded female mixed with a male voice, and more sounds like gunshots.  Since there is no explanation for the first sounds if they were not gunshots, and the gunshots fired killed Steenkamp, then it follows that Pistorius was making the screams and that his cricket bat on the door sounded like gunshots.  You can listen to the sounds of a gun and a cricket bat against a door here and decide for yourself whether they might be conflated.

Thus, the evidence of Stander, Johan Stipp, and Anette Stipp, that they heard gunshots, then female screaming (mixed with a male voice according to the Stipps), then more gunshots, suggests to me that they might have misheard what were in fact gunshots, then Pistorius screaming, then his cricket bat against the door.  The logic is that there is no explanation for what the first sounds like gunshots were, if they were not the gunshots that killed Steenkamp.

Burger and Johnson, further away, were woken by the sounds of a female scream and a male calling for help, then gunshots.  In light of the evidence of Stander and the Stipps, is it not plausible that Burger and Johnson actually heard the sounds of Pistorius screaming, then his cricket bat, in spite of Johnson's adamant denial of that possibility?  Is it plausible that Burger and Johnson would be woken up by screaming but not by previous gunshots?

On the other hand, Van Der Merwe heard loud talking for an hour before gunshots.  She was the only witness who reported being awake to hear this long period of sounds prior to the others being woken.

In sum, based on my reading of these witness statements, I think there is reasonable doubt to suggest that the screams that were heard before the second series of sounds like gunshots were in fact produced by Pistorius, and that those second sounds were made by his cricket bat.  Stander and the Stipps seem to confirm the possibility of mishearing, on the logic that the first gunshot sounds were the shots that killed Steenkamp.  Otherwise, what were those first sounds?  Has any suggestion been made?

Therefore, the general trend of the evidence of the majority of "ear-witnesses" does not seem to me at the moment to support the case that Pistorius shot Steenkamp after she screamed.  Certainly not beyond a reasonable doubt.  Only Van Der Merwe's evidence contradicts this, since she can hardly have heard the cricket bat but not gunshots.  Her testimony seems to me to be a bad fit with that of the others.

If we go with the apparent import of the testimony of the majority of the witnesses, then they did not provide evidence to support the charge of premeditated murder.  Only Van Der Merwe's evidence does so, if she was indeed hearing Pistorius and Steenkamp: the defence claimed tests showed she could not in fact have heard them.

According to my inexpert and limited analysis of the witness evidence, therefore, it would seem there is reasonable doubt on the premeditated murder charge.  Although Pistorius' actions seem bizarre, are they so bizarre as to justify a premeditated murder conviction without supporting witness evidence?  Is there other relevant evidence to consider concerning this most serious charge?  I am always willing to change my mind based on more evidence or better interpretation.  I am less willing to let evidence as to a suspect's character or general demeanour determine my mind about what he might have done on a given occasion.  Moreover, my provisional conclusion that there is reasonable doubt as to Pistorius' guilt on the most serious charge is not the same as having evidence of his innocence of that charge.

Was the judge right to let Pistorius off the lesser spur-of-the-moment murder charge because he would not have foreseen killing whoever was behind the door?  I don't know; it seems a strange conclusion.  I expect Pistorius to be found guilty of manslaughter (culpable homicide) tomorrow, and either this result or the lesser murder charge seem to be more in line with what can be deduced from the witnesses' evidence without drawing more serious but dubious conclusions.

Finally, let's just plug in some numbers to derive a Bayesian probability of Pistorius having shot Steenkamp after she was screaming, and thus being guilty of premeditated murder.  (I explained and used Bayes' Theorem previously.)  The prior probability of guilt based on the inherent improbability of Pistorius' story I shall call 90%.  The probability of the witness evidence being what it is on the hypothesis of innocence of the most serious charge I would call 100%, since I disregard as mistaken the witness reports of hearing female screams after the first gunshots.  Van Der Merwe I don't find reliable enough to count.  And on the hypothesis of guilt, I call the probability of the witness evidence 90%, to allow for the thought that if the couple were arguing so badly as to put Pistorius in a murderous state of mind then we might expect such an argument to have woken more and nearer neighbours before shots were fired.  Plugging these numbers into the Bayesian calculator, we get: 89%.  In other words, given the almost indifferent import of the witness evidence, one's judgement of the likelihood of guilt depends almost entirely on how (im)plausible one finds Pistorius' story, and I find it pretty implausible.  If it is sufficiently inherently unlikely that Pistorius would shoot an intruder in the bathroom without checking that it was not Steenkamp in there, then that alone makes him highly likely to be guilty.  But could we justly convict him based on the bizarreness of his story alone?

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