The 33-year-old, who is the most prolific child serial killer in modern British history, was handed a whole-life order at Manchester Crown Court on Monday, after being convicted of seven counts of murder and seven counts of attempted murder in relation to six other infants while working at the Countess of Chester Hospital neonatal unit between 2015-2016.
Letby joins a macabre list of child killers including Moors murderers Ian Brady and Myra Hindley and the so-called Angel of Death paediatric nurse Beverley Allitt.
The nurse refused take part in her sentencing hearing, leaving the dock empty as her sentence was passed, with families of her victims forced to address an empty dock as they told her "you are nothing" and "you are evil".
Letby's absence sparked anger and reignited calls for changes to the law to force criminals to attend court for their sentencing, with Prime Minister Rishi Sunak branding her "cowardly".
Why couldn't Letby be forced to attend her own sentencing?
The court has no power to force a defendant to attend a sentencing hearing, but a government source had suggested that "lawful enforcement" could be used as a last resort to ensure Letby attended if it was considered necessary, reasonable and proportionate.
"Lucy Letby should be in court to hear society’s condemnation of the enormity of her crimes, expressed by the judge,” the source told the PA news agency ahead of the hearing, saying Letby's refusal would "only strengthen our resolve to change the law as soon as we can".
Watch: Bereaved families demand new law as baby serial killer set to snub sentencing
Former justice secretary Robert Buckland called for the sentencing to be played into Letby’s cell if she does not attend, regardless of her wishes, and said she should have to listen to victim statements from the families of the babies she murdered.
He told GB News: "She needs to hear the victim’s personal statements, as impact statements that will really bring home I think, to the wider world, the appalling devastating impact of the loss of these innocent children, these innocent babies, have had upon dozens of families."
Which other killers missed their sentencing?
Earlier this year, Justice Secretary Alex Chalk said the government was "committed" to changing the law so criminals are compelled to attend their sentencing hearings, and MPs and relatives have now called for new legislation to be fast-tracked after Letby became the latest criminal to refuse to attend their sentencing.
Earlier this year, Thomas Cashman refused to leave his cell to be sentenced for the murder of nine-year-old Olivia Pratt-Korbel, prompting the trial judge to brand his absence "disrespectful".
Other defendants who refused to be in court for their sentencing include the brother of Manchester Arena bomber Hashem Abedi, and serial offender Jordan McSweeney, who sexually assaulted and murdered 35-year-old Zara Aleena as she walked home in June 2022.
A campaign dubbed 'Face the Family', which includes a petition to the government, is calling for a change to the law to order offenders to appear in court - as well as allowing prison and court staff to be given powers to use reasonable force to get offenders into the dock, in the same way they do to transfer them from a court to prison.
A response from the Ministry of Justice to the petition, posted on 18 August, says: "The government is carefully considering changing the law so that offenders are required to face up to their actions and victims can see justice being served.
"The government fully appreciates that an offender’s refusal to attend their sentencing hearing can cause enormous upset and anger for victims and their families.
"That is why, during his leadership bid, the Prime Minister committed to making offenders spend longer in prison for non-attendance, and the Lord Chancellor confirmed in April that the Government will bring forward legislation to deliver this change as soon as parliamentary time allows.
"Under the current law, courts can ensure in most cases that offenders appear to face the consequences of their crimes. However, it is the case that an offender who is being held in prison on remand cannot currently be forced to attend their sentencing hearing. We are therefore carefully considering how best to address this issue."
Watch: Olivia Pratt-Korbel's mother calls for sentencing law change
It said while in some cases have an offender present would give victims closure, there might be some cases where they would be disruptive or cause delays, adding to distress, so courts should have the discretion to do what is right in each case.
"Victims remain at the heart of this government’s priorities," the response said. "We are committed to ensuring that offenders are required to face up to their actions and victims can see justice being served and, as we have made clear, will be bringing forward legislation as soon as possible to address the issue of non-attendance at sentencing hearings."
What made Lucy Letby a killer?
Letby used various ways to harm babies in her care, including injecting air into the bloodstream or stomach, overfeeding with milk, physical assaults and poisoning with insulin.
The nurse falsified medical notes to cover her tracks and gaslighted doctors and nurses to persuade them the collapses were "just a run of bad luck", the court heard.
She then went on to carry out numerous Facebook searches for parents of children she attacked.
It has emerged that consultants raised concerns about Letby as far back as 2015 but police were only contacted in 2017, and she was then arrested in July 2018.
Searches of her home revealed a number of written notes - on one she had written: "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" and in capital letters "I am evil I did this".
It has been claimed that babies could have been saved if hospital management had listened and acted sooner.
The government has announced an independent inquiry into the case, but Steve Brine, chairman of the Health Select Committee, has called for a judge-led statutory inquiry, while police have also been urged to investigate hospital bosses for potential corporate manslaughter.
Cheshire Police say they are continuing to review the care of some 4,000 babies who were admitted to the Countess of Chester, and also at Liverpool Women’s Hospital when Letby had two work placements, during her employment from 2012.
Will Lucy Letby ever get released?
Letby has been sentenced to a whole-life order - the most severe punishment available in the UK criminal justice system.
Prisoners given a whole-life order are never considered for release unless there are exceptional compassionate grounds to warrant it.
Under the Police, Crime, Sentencing and Courts Bill, which passed through Parliament last year, the government expanded the use of whole-life orders for premeditated murder of a child.
Only three women have previously been handed a whole-life order – Hindley, who died in 2002, and serial killers Rose West and Joanna Dennehy.
Sentencing Letby, Mr Justice Goss said: “There was a malevolence bordering on sadism in your actions.
"During the course of this trial you have coldly denied any responsibility for your wrongdoing.
"You have no remorse. There are no mitigating factors."
Handing her a whole-life order for each offence, he said: "You will spend the rest of your life in prison."