"Rogue nurse" Lucy Letby has been convicted of murdering seven babies and trying to kill six others at a Cheshire hospital neonatal unit.
Letby, 33, described as a "calculated opportunist", used several ways to inflict harm on the children including injecting air intravenously and administering air and/or milk into their stomachs.
In a murder trial which started last October, making it one of the longest in UK history, Letby was accused of deliberately harming the babies while she worked on the neonatal unit at the Countess of Chester Hospital.
She also allegedly added insulin as a poison to intravenous feeds, interfered with breathing tubes and inflicted trauma in some cases.
Letby denied all the allegations, but following 22 days of deliberations, the jury found her guilty of seven counts of murder, making her the UK's most prolific child serial killer in modern times.
Watch: Video shows moment Lucy Letby is arrested on suspicion of murder
Crown Prosecutor Pascale Jones said of Letby: “In her hands, innocuous substances like air, milk, fluids - or medication like insulin - would become lethal. She perverted her learning and weaponised her craft to inflict harm, grief and death.
“Time and again, she harmed babies, in an environment which should have been safe for them and their families.”
Letby was not in the dock when the jury was discharged on Friday after finding her guilty of murdering seven babies and attempting to murder six others.
Her parents were also absent from the court, but families of the victims were in the public gallery.
After the jury confirmed they were unable to reach verdicts on six charges of attempted murder in relation to four babies, the relatives of one of the infants stormed out of court.
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Verdicts on 16 of the 22 counts she faced were returned by the jury on earlier days, but could not be reported until now.
When the first two guilty verdicts were returned, to two counts of attempted murder, on 8 August, Letby fought back tears in the dock and then cried as she left the courtroom.
During the long-running trial, the jury heard about each one of the babies, who were referred to as Child A through to Child Q, that Letby was said to have tried to harm.
The court was also told about social media searches Letby made following the infants' deaths, and a sympathy card she sent to parents of one child she was accused of trying to harm.
But Letby denied doing anything harmful to any child and said their sudden collapses and deaths could have been due to natural causes, or for some unascertained reason, or from failure by others to provide appropriate care.
The defence said she was a “hard-working, dedicated and caring” nurse who loved her job.
In a statement read outside court, Det Ch Insp Nicola Evans, of Cheshire Police, said: “All of their babies will forever be in our hearts.
"I cannot begin to imagine how the families in this case feel today, I just hope that today’s verdicts bring all of them some peace of mind for the future, and that we have answered some of the questions that they were looking for."
How was Lucy Letby caught?
Letby was the only member of the nursing and clinical staff on duty each time the collapses happened, which prosecutors argued were not natural events.
She used various ways to harm the babies including injecting air into the bloodstream, injecting air into the stomach, overfeeding with milk, physical assaults and poisoning with insulin.
Some of the children were subjected to repeated attempts to kill them by the “cold, cruel and relentless” band 5 staff nurse, the trial - which began at Manchester Crown Court on 10 October last year - heard.
Letby’s presence when collapses took place was first mentioned to senior management by the unit’s head consultant in June 2015.
Concerns among some consultants about the defendant increased and were voiced to hospital bosses when more unexplained and unusual collapses followed, the court heard.
But Letby was not removed from the unit until after the deaths of two triplet boys and the collapse of another baby boy on three successive days in June 2016.
Letby was confined to clerical work and in September 2016 registered a grievance procedure.
Watch: Parents of twins targeted by Lucy Letby speak of experience
It emerged during legal argument in the trial – in the absence of the jury – that the grievance procedure was resolved in Letby’s favour in December 2016.
Letby was due to return to the neonatal unit in March 2017, but the move did not take place as soon after police were contacted by the hospital trust.
The nurse was arrested at her semi-detached home in Westbourne Road, Chester, at 6am on 3 July, 2018.
During searches of her address, a number of closely written notes were discovered.
What were Lucy Letby's motives?
The reason why nurse Lucy Letby went on a killing spree at a hospital neonatal unit may never be known, say detectives.
Prosecutors did not advance a motive as they outlined the allegations against her to the jury of eight women and four men.
Trial judge Mr Justice Goss told jurors they have did not have to be sure of the motive or motives for deliberately harming a baby.
He said: “Motives for criminal behaviour are sometimes complex and not always clear. You only have to make decisions on those matters that will enable you to say whether the defendant is guilty or not of the particular charge you are considering.
“Any decision you do make must be based on evidence and not speculation.”
Speaking after the case, senior investigating officer Det Supt Paul Hughes said: “Ultimately, the only person who can answer the question ‘why?’ is Lucy Letby herself.
“I don’t think we’ll ever know unless she chooses to tell us.”
Letby may have been motivated by a “pathological desire for attention and sympathy”, a criminology expert has said.
Dr Dominic Willmott, a senior lecturer in criminology at Loughborough University, said the former nurse’s text messages showed she wanted to “garner sympathy” from colleagues after the children’s deaths.
The expert told how there were “clear similarities” with the Letby case and historic cases of killer nurses, such as Beverley Allitt from the UK and Charles Cullen in the US.
Allitt, 54, targeted 13 victims during a 59-day spree which saw her kill four babies and poison nine others at Grantham and Kesteven Hospital, Lincolnshire, in 1991.
Doctors believe she suffered from Munchausen syndrome by proxy while carrying out the attacks, in which a caregiver may harm someone in their care to get attention.