Nurse Lucy Letby is on trial accused of the murder of seven babies and the attempted murder of 10 others.
Letby, 32, denies murdering five boys and two girls, and attempting to murder another five boys and five girls between June 2015 and June 2016.
At the time, she worked in the neonatal unit of the Countess of Chester Hospital in Chester.
On Thursday the prosecution concluded their opening arguments and the defence opened theirs.
"I am evil I did this"
A note found in Letby's house with the words "I am evil I did this" in capital letters written on it was shown to the jury on Thursday.
Another saying "I don’t deserve to live. I killed them on purpose because I’m not good enough to care for them. I am a horrible evil person," was also shown to Manchester Crown Court.
The notes were among other papers and Post-it notes which also contained "many protestations of innocence", Nick Johnson KC, prosecuting, told the jury.
Paperwork relating to many of the children who died or suffered collapses was found along with Post-it notes with closely written words which included the names of some of her colleagues, the court heard.
The prosecutor said that in her writings Letby expressed frustration because she was not being allowed back on the neonatal unit and wrote: "I haven’t done anything wrong and they have no evidence so why have I had to hide away?"
The defence opens its arguments
Ben Myers KC, representing Letby, gave a short introduction to her defence case and told jurors anyone who approached the matter "as some kind of done deal has got this very badly wrong."
"She loved her job. She cared deeply about the babies and also cared for their families."
He said: "There is a real danger that people will simply accept the prosecution theory of guilt and that’s all we have so far, ladies and gentlemen, a theory of guilt based firmly on coincidence – if anything can be based firmly on coincidence."
Others made mistakes
Core to the defence's argument was the notion Letby was being blamed for the mistakes of others.
Myers pointing to Letby sitting in the dock, told jurors: “It is important to be careful that blame is not heaped on that woman when there may be others who have made mistakes or a system which has failed.”
In some cases, the defence say, no-one could say why a particular child deteriorated or died.
He added: "The fact that Lucy Letby has been present at the time of the deterioration of a child has itself become the explanation of that deterioration, even though there’s no evidence to show she has caused that to happen."
What the defence said about the notes
Explaining the Post-it note, he said: "This is the anguished outpouring of a young woman in fear and despair when she realises the enormity of what’s being said about her, in the moment, to herself."
Mr Myers said at the time it was written she was dealing with employment issues, including a grievance procedure with the NHS trust.
He went on: "This whole case is complicated.
"Sat in that dock is a young woman who says this is not her fault, so we need to look at the evidence."
The trial continues.