Lucy Letby
BBC Reporter Judith Moritz (reviewing social media posts on a ostentatiously product-placed MacBook):
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The JC Sounds Off™
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“We’ve found a witch. May we burn her?”
- — Peasant, Monty Python and the Holy Grail
“There are ways of telling she’s a witch”
“Sparky, full of fun, popular — she looks like the life and soul of the party in these photos. I don’t know what Britain’s most prolific child killer should look like. I’m pretty sure it’s not this, though.
“She comes across as — mousy; a bit normal — you can’t really marry that with the enormity of what she’s been accused of.”
This fits two profiles: either this is some cold, callous, monstrous psychopath — or a perfectly ordinary young woman. You know — a sparky, fun, popular young woman. The life and soul of the party.
On herd minds, groupthink and narrative bias
Lucy Letby’s case is in the news. Those internet citizens who have taken more than a passing interest have divided into opposing camps: a large preponderance for whom she is a cold-blooded monster and a small band who, based on advanced statistical techniques, have questioned the safety of her conviction. Those have tended to quickly spill over from scepticism about the strength of a positive case into the full-throated conviction about a negative one: they are certain, beyond a reasonable doubt, that Lucy Letby is positively innocent of all charges.
JC has his opinions, which we will get to, but the first step is to keep an open mind. Innocence and guilt beyond reasonable doubt leave a wide range of ambivalent attitudes between.
Bu humans like our narratives to tell us meaningful things about the world, and that means ruling other things out. A narrative that says, “huh, who knows?” is not wildly instructive. It doesn’t tell us much about the world. It offers little intellectual satisfaction.
But it may be the best we can reasonably expect.
The problem with “conviction” and “innocence” narratives is that they become self-fulfilling. Once you form a view you can panel-beat a great range of subsequently occurring information so it suits your view. Especially ambivalent information that doesn’t really help one way or another.
The mechanisms by which we do this are biases — either confirmation bias — a well-documented logical fallacy — or its less-understood converse: ignorance bias,[1] whereby we ignore information that does not support our theory, or tends to contradict it.
Both can serve either certainty: that Lucy Letby is a serial killer, or the victim of a grave injustice. Both standpoints are equally emotive. There is no comfortable centre to hold here.
Standpoint intersection ahoy
We are at the intersection of at least four discrete fields of intellectual enquiry here: law, medicine, statistics and ethics. They are not commensurate — they each have their own rules, customs and institutions and authority in one does not commute to the others. In a perfect world their outcomes would converge, but the world is not perfect. There will be circumstances in which the correct legal outcome is not morally right, the correct moral outcome is not borne by the statistics, the statistics are at odds with our knowledge, and vice versa. There is little wonder good people get upset.
There is even room for epistemology. You cannot but frame your understanding of the overall scenario through one or other of those prisms. Or a combination, but that is liable to lead to conflict. There is no transcendent, neutral frame of reference by which the others may be judged. Without a framework the territory is random, incoherent noise.
For the scenario is one that unusually uncertain, about which the prospect of consensus is unusually low. It is not even clear that there was a wrongful killing here, let alone by whom.
Careful of that narrative, Eugene
And there is a more visceral narrative frame at play, too, for the way the system has behaved Lucy Letby is either a monster or a scapegoat — there is no middle ground, where she is an ordinary kid, with her pluses and minuses, virtues and failings, just like the rest of us, available to her. She is either angel or devil. Given the probabilities at play — 99% of the population are neither — this seems an injustice in itself.
The hard-edged peripheral evidence we do have can and has been coloured through that lens. Her apparently vivacious personality and active social life marks her out as a psychopath — corroborates her wickedness — or illustrates the single-mindedness with which a vicious system will crush an innocent, unsuspecting spirit. That she searched online for the parents of the deceased is consistent with either breathtaking malevolence — if she is guilty — or affecting compassion if she is not. Unless evidence can be shown that no innocent carer ever sought out her patients relatives on line, it is evidence of neither. We all Google individuals we meet in real life. This is perfectly normal behaviour.
Substance, form and process
The first thing to bear in mind is the difference between the substantive — the wilful morally unjustified ending of a life (this is an ethical frame of reference), the formal — the commission of the act of murder as defined in law (in some ways an ethicist’s map of the territory: a systematic way of economically delivering that ethical framework), and the procedural — the process one must gone through to determine whether a murder was committed. This includes the the presumption of innocence, the adversarial tradition, the laws of evidence, the rules of court procedure, and tactics and strategies that defence and prosecution teams adopt within that milieu to best present their case, whose outcome is ultimately determined not by judges, lawyers, ethicists statisticians, physicians or metaphysicians but by 12 ordinary people, who may have none of these skills, drawn at random from the electoral roll.
These are different questions, with different considerations, and it is important they are not confused. A person who murders unobserved in cold blood, leaves no evidence, and has no motive cannot be convicted beyond reasonable doubt of murder unless no other explanation is possible. The procedural element fails: there is not enough evidence. A person who kills in cold blood, before witnesses but in demonstrable, reasonable self-defence, cannot be convicted of murder because the formal elements are not met. She has a defence.
Our justice system is meant to benefit the accused in marginal cases: we regard acquitting the occasional perpetrator as a lesser evil than convicting a single innocent. But even then we get it wrong sometimes. Cases involving medical misadventure and statistics are a recurring case of injustice.
Where, as in these cases, there is no “direct” evidence, the form and procedure becomes all the more important.
In Lucy Letby’s case there is no direct evidence definitively linking her to a single murder. There is no direct evidence unequivocally suggesting there was a murder — as opposed to misadventure, negligence or even inadvertent accident — at all. But by the same token nor is there unequivocal evidence that any of these were not murders, nor that, if they were, Letby did not commit them.
The internet is polarised around two highly unlikely contingencies.
It is logically possible she did commit the murders, logically possible she did not, and logically possible she played a role in some or all of the deaths that did not amount to murder.
The question of whether she should be convicted comes down, at some point, to an estimation of probabilities. These inform how “sure” one can be about the proposition “defendant murdered victim”.
These murder cases have an unusually wide range of unknowns. It is unclear whether there was any murder at all. The deaths could have been innocent, and they could have been culpable to some legal standard short of murder (negligence, for example)
If you conclude that “foul play” (including negligence) is at work there is then the question of who did it. Did other personnel have an opportunity?
Emergence
There is a kind of meta-statistics at play here too. For even if there is reasonable doubt for every individual case the unusual repetition of cases creates its own meta narrative. Roll once and get a six, and there is no surprise. Roll three sixes Each of these enquiries requires an answer “beyond reasonable doubt”. If a victim dies in the presence of a single person with a means and motive, such that if the death was intentional there is no other possible suspect, if there is a reasonable doubt as to the death being natural — even if it probably was not — there can be no conviction.
“Once is happenstance. Twice is coincidence. Three times is enemy action.” — Ian Fleming, Goldfinger (1959)
Here is where a sequence makes a difference. One such occurrence might be improbable, five occurrences extremely improbable, 500,
So
What are the percentages of serial killers with history of broken homes, physical or sexual abuse, and mental illness? What percentage are female?
“God complex”
Killing people is not evidence of a God complex. The basest criminal can take life. Bringing people back to life — that is evidence of a God complex.
Evidence
Insulin “smoking gun”
In two cases (Child F and Child L) lab tests indicating high levels of insulin without accompanying c-peptide, which is prime facie evidence of administered insulin (naturally occurring insulin is accompanied by c-peptides; artificially administered insulin is not). Insulin was not prescribed for either infant. If it was true that insulin was added without prescription this is evidence of actual human agency in these two episodes.
The defence team accepted the prosecution’s claim that insulin was added to parenteral nutrition bags and it was presented to the court as an agreed fact.[2]
- The test in question was not reliable for factitious insulin. From the label:
“Please note that the insulin assay performed at RLUH is not suitable for the investigation of factitious hypoglycaemia. If exogenous insulin administration is suspected as the cause of hypoglycaemia, please inform the laboratory so that the sample can be referred externally for analysis.”
- The test results seem to indicate very high levels of insulin: 4657 pmol/L is about four times a dangerously high level in an adult.[3] While, yes, this is what you might expect a murderer to try to do —
- Both babies recovered: You might expect premature babies registering such high insulin levels — four times a critical level for an adult[4] — might have at least caused a fuss at the hospital. But not only did the babies make a full recovery, with no record of hypoglycemic coma, but —
- No-one even noticed the high insulin in their tests until 2018: That is, three years after the babies made a full recovery. If you are looking for a res ipsa loquitur about these events, can we suggest that this is as indicative of negligence in the clinical staff administering the test, or the self-professed unreliability of the tests for detecting factitious insulin.
The Texas sharpshooter
See the TriedbyStats website: Over 730 shifts, with 38 “suspects” If you self-select one
The victim’s families
There are unquestionable victims here: the families. If Lucy Letby wasn’t responsible then this was either an unavoidable accident, in which case, there is no closure, or there is another culpable explanation — an alternative murderer seems extremely implausible — but medical misadventure of some kind is not. Difficult
The post-it note
Everyone seems to accept the notes are highly inclusive and of little evidential value.
“The ramblings of someone under extreme psychological pressure.”
Resources
Online
- That New Yorker Article (choose your own snapshot from the Wayback Machine)
- Mephitis - The Lucy Letby Case May In Time Be The Story Of The Century
- TriedbyStats
- The Insulin ‘Evidence’ in the Lucy Letby Trial. Criminal Justice in England: Disagreeable Facts
Podcasts
- We need to talk about Lucy Letby (Peter Elston and Michael McConville podcast)
- The Trial of Lucy Letby (Daily Mail podcast)
See also
References
- ↑ JC made this term up.
- ↑ Science on Trial
- ↑ There is plenty of online angst about whether the level recorded was abnormally high or absurdly high, such that such a level had never been witnessed in medical history: let’s go with abnormally high.
- ↑ See: Very Well Health: Hyperinsulinema (High Insulin Levels).