With Shipman, there were red flags through his work as a Dr. He was addicted to and prescribing himself pethidine fraudulently in the 1970s. He was sacked by the practice he worked for and disciplined by the GMC but not struck off. That's a biggie for a start. That shows he had mental health i.e addiction problems and used his position as a Dr to commit crimes to feed his addiction.
Many years later, a number of individuals, some professionals and some not, reported unusually high death rates for patients that Shipman in particular was signing death and cremation certificates for, and suspiciously, wills made leaving money to Shipman.
They were 'smoking guns' and upon serious investigation by the Police, evidence of fraudulent signing of wills was clear, exhumation of body's occurred and charges were made.
That didn't happen with Lucy Letby. There was an elevated death rate on the unit she worked on which was reviewed by external agencies like the Royal College of Paediatrics and child health who could not come up with any reason, given all the medical evidence, for why the babies had died. As the medical evidence found nothing ouside of natural causes.
So there was no evidence of crimes. And certainly no evidence of a particular individual killing babies.
But some people had possibly valid suspicions that crimes were committed and that Lucy was the likely perpetrator based on circumstances.
And the Police reverse-engineered a case. They didn't begin as is usual, with singificant evidence of a crime and significant evidence tying a suspect to that crime.
They started off trying to prove crimes had been committed with a suspect already in mind.
That's why many people have reservations about this case. It's why the Police and CPS spent years building a case before charging and taking to court. And why it was an incredibly long court case based on 'expert' evidence which virtually no individual or jury could understand, accept or discount unless they were experts themselves.
It's got nothing to do with not thinking Lucy was a lovely white girl so couldn't have done it, or not understanding her motivation, or any other things. Including 'wanting to defend a serial killer'. I mean, come on, why would someone want to do that?
It's to do with thinking that just maybe, a miscarriage of justice may have happened.
And that's worrying for all of society.