When police raided the home of British nurse Lucy Letby, they discovered a haunting green post-it note tucked inside the pages of her personal diary.
It proved to be a damning clue which pointed to the hideous crimes carried out by Letby against helpless babies inside the Countess of Chester Hospital between 2015 and 2016.
Underneath a title of "Not Good Enough" on the note, Letby scrawled all kinds of phrases and words, including: "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."
During her trial, where the 33-year-old was found guilty of murdering seven babies and attempting to kill six others, the prosecutor framed the note as "literally a confession".
Other disturbing messages on the note read: "I AM EVIL, I DID THIS. There are no words. I am an awful person – I pay every day for that. I can't breathe. I can't focus. Kill myself right now. Overwhelming fear/panic. I'll never have children or marry. I'll never know what it's like to have a family. NO HOPE."
Letby's diary, which hid the chilling note, was childlike in design and appearance.
Its colour palette was all soft pastels, shades of blues and pinks.
A knitted soft toy puppy dog - the kind you might find in a cot, nestled in against the body of a sleeping child - was the cover's hero.
The brown-eyed, floppy-eared dog is holding a simple flower.
The words "Have a lovely year!" were printed across the top of the ring bound 2016 diary.
The truth was, because of Letby's sustained evil actions inside the neonatal unit where she worked, crushed families were suffering a living hell.
Beginning in 2015, the Countess of Chester Hospital saw a significant rise in the number of babies who were dying or suffering serious catastrophic collapses.
It wasn't clear yet, but Letby was the common denominator.
She had secretly attacked 13 babies on the neonatal ward at the Countess of Chester hospital between 2015 and 2016.
"In her hands, innocuous substances like air, milk, fluids – or medication like insulin – would become lethal," Pascale Jones of Britain's Crown Prosecution Service would later say in court, after investigators pieced the horrible puzzle together.
"She perverted her learning and weaponised her craft to inflict harm, grief and death."
Letby's sick intention was to kill the babies while duping her colleagues into believing there was a natural cause of death.
With the successful conviction of Letby, where parents gave harrowing testimony of mysteriously losing their newborns in the neonatal unit, attention is turning on hospital's procedures and management, and their potential culpability in the murders.
Consultants had raised their concerns over the increased mortality rate of patients under Letby's care, but they were initially dismissed by the hospital's management.
In September 2016, Letby filed a grievance against her employers after she was relocated away from the hospital's neonatal ward.
She was put back on clerical duties after two male triplets died and a baby boy collapsed on three days in a row in June 2016.
Later that year, she was notified of the allegations against her by the Royal College of Nursing union, but the complaint was later resolved in her favour.
In a dark twist, doctors were asked to formally apologise to Letby in writing.
She was scheduled to return to the neonatal department in March 2017, but mercifully her return never happened.
Instead, the hospital trust contacted the police, who opened an investigation.
She was arrested again in November 2020.
During their investigation, police found records Letby had taken home from the hospital on babies who had collapsed.
Detectives learned Letby had performed thousands of searches online for information about the parents after the killings.
Letby attacked babies by injecting intravenous lines with air, poisoning some with insulin and force-feeding others milk.
After killing them, she sometimes sobbed in grief, made keepsakes for parents and bathed the little bodies and dressed them for burial.
The victims, who were given anonymity and listed only by letters, such as Child A and Child B, died in the neonatal unit.
"I don't think we will ever get over the fact that our daughter was tortured till she had no fight left in her and everything she went through over her short life was deliberately done by someone who was supposed to protect her and help her come home where she belonged," the mother of a girl identified as Child I said in a statement read in court.
The judge said no one but Letby knows what drove her, though some parents ventured theories: she wanted to play god; she needed attention, drama and sympathy in her life; or she wanted to be remembered.
The parents of several of the babies that survived Letby's assaults said their children now require around-the-clock care.
Today, Letby was sentenced to life in prison without the possibility of parole.
She was handed a whole life order by Manchester Crown Court, meaning she will never be released.
Letby refused to appear in the dock, prompting calls for laws to be changed so that defendants must attend their sentencing hearings.
Explaining why he decided Letby must spend the rest of her life in prison, Justice James Goss called it "a cruel, calculated and cynical campaign of child murder involving the smallest and most vulnerable of children".
Goss addressed Letby as if she was in court during the sentencing.
He ordered his remarks and the victim impact statements read in court earlier in the day to be handed to the convicted serial killer.
"There was a deep malevolence bordering on sadism," he said.
"During the course of this trial you have coldly denied any responsibility for your wrongdoing. You have no remorse. There are no mitigating factors."
- Reported with agencies