I went down the rabbit hole on this a couple of months ago. Some of the details are a bit hazy in my memory now as it was about 2 months ago, but in the interest of playing devil's advocate...

> the suspicious deaths all lined up perfectly with Lucy Letby's shifts

Once a nurse has been around the ward for long enough to have seen several deaths, you can produce a table showing a set of baby deaths correlating to any nurse's shifts [1]. The ward was for seriously ill newborn babies, so baby deaths were unfortunately common, and each nurse would regularly be on shifts where one would die.

As you say, these deaths were considered "suspicious", but some (e.g. [2]) claim otherwise, saying key tests that would rule the accused method of murder in or out were not done at the time of death.

> she was often caught interacting with those babies when she had been instructed not to

(Again, playing devil's advocate) the job selects for nurses who (apart from Letby, it seems) deeply care for young babies. Not a smoking gun.

> when she was taken off the ward the deaths instantly stopped

This has been contested. As far I can tell the hospital's death rate statistics disagree with the Office for National Statistics. The latter's data appears to show the deaths peaked after Letby was taken off the ward [3] (note, I haven't checked the underlying source mentioned in the tweet).

Replies to some comments below yours:

> And she took home documents from several of those patients, which she'd have no ordinary reason to have fished out of the trash.

Apparently this is quite common for nurses working on this and other intensive care wards. Nurses just off duty are often phoned by the nurses who took over the shift, asking for details on particular babies' treatment or behaviours that day. Having files on the babies to hand would let Letby give exact details without having to remember or misremember them.

> And the little old thing that she wrote "I killed them on purpose" on a post-it-note at her house.

This looks bad, yes, but again not a smoking gun. I think I read this happened after she was already taken off the ward or had somehow found out she was under investigation for causing baby deaths. I could believe a note like that could be written by someone on the verge of a breakdown or under extreme stress. The "I killed them" bit I could believe someone could write if they regret not having spotted something earlier that someone more experienced might have, especially if they have imposter syndrome.

As the blog makes clear, it's not really about whether Letby is innocent or guilty, it's about whether she got a fair trial. It seems many statistics were misused in her case, circumstantial evidence was used as smoking guns, and some evidence was not fully addressed [4]; basically enough to question the verdict.

[1] https://twitter.com/profnfenton/status/1692837686166368660

[2] https://gill1109.com/2023/05/24/the-lucy-letby-case/

[3] https://twitter.com/LawHealthTech/status/1692917506078376019

[4] Apparently during the trial it was mentioned that sewage pipes crossed the ceiling and backflow sometimes came into the sinks. Definitely not a good mix to have in a ward with very ill babies. Hopefully infection spread from bad plumbing was fully ruled out as causes of death during the trial. Some critics don't seem to think it was.