A nurse from Hereford accused of murdering seven babies allegedly left a handwritten note confessing to her crimes that read "I AM EVIL I DID THIS".
Lucy Letby, 32, is alleged to have gone on a year-long killing spree while working at the Countess of Chester Hospital.
She is also accused of the attempted murder of 10 other babies.
On Thursday morning, on the fourth day of her trial, the prosecution concluded its opening statement, in which the case against Letby was laid out.
Nick Johnson KC finished by telling Manchester Crown Court about a series of handwritten notes and Post-Its found during a search of her home.
On one green post it note - which was shown to the court - she had written: "I don't deserve to live. I killed them on purpose because I'm not good enough."
She also wrote: "I am a horrible evil person" and in capital letters, "I AM EVIL I DID THIS".
There was no reaction from Letby as her alleged confession was read out.
Over the past four days, the 22 charges against Letby have been described in court.
Letby, of Hereford, has pleaded not guilty to all counts.
The children and their families are not being named by the media and so are referred as Children A to Q.
One, Child P, was one of two triplets the prosecution claims were killed by Letby. Their brother survived as he was in another room.
A day after Child P died, Child Q was sabotaged, allegedly, by Letby.
Mr Johnson said Letby falsified medical records to give herself an alibi at the time of Child Q's sudden collapse.
Apart from three days the following week, this was to be the last time Letby would work at the neonatal unit at the Countess of Chester Hospital.
The defence is now due to begin its opening argument before the main evidence portion of the trial begins.
Doctors grew suspicious about 'cold-blooded' Letby
"Cold-blooded" Letby tried to kill one "resilient" newborn girl four times "before succeeding", the court was told.
The nurse was also questioned by police about why she had sent a sympathy card to the baby's parents.
By April 2016, consultants at the hospital had grown suspicious of Letby - moving her off night shifts over concern about the "correlation between her presence and unexpected deaths/life-threatening episodes".
One consultant began to feel "uncomfortable" when he realised Letby was alone with the child. When he walked into the room, he noted that the infant's breathing tube was dislodged.
"We alleged she was trying to kill Child K when the paediatric consultant walked in on her," Mr Johnson told the court.
The trial continues.