Lucy Letby has been convicted of murdering seven babies and attempting to kill six others at a hospital neonatal unit.

Prosecutors said Letby, 33, was a “calculated opportunist” who used the vulnerabilities of premature and sick infants to camouflage her acts.

In 2015 and 2016, there was a significant rise in the numbers of babies who suffered serious and unexpected collapses in the neonatal unit at the Countess of Chester Hospital.

Letby was the only member of the nursing and clinical staff who was on duty each time the collapses happened, which the Crown 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 last October – heard.

Letby’s presence when collapses took place was first mentioned to senior management by the unit’s head consultant in late 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.

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 July 3 2018.

During searches of her address, a number of closely written notes were discovered.

On one green Post-it note she wrote: “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”.

Prosecutor Nick Johnson KC invited the jurors to read the note “literally” as a confession.

Also found during searches, the court heard, were more than 250 shift handover sheets containing names of some of the children on the trial indictment.

Mr Johnson said “voyeuristic tendencies” drove her to carry out numerous Facebook searches for parents of children she attacked.

The “rogue nurse” falsified medical notes to cover her tracks and also gaslighted doctors and nurses to persuade them the collapses were “just a run of bad luck”.

She was also prepared to publicly trash the reputations of colleagues “in an effort to get away with it”, the prosecutor added.

Letby, from Hereford, denied all the allegations.

The jury of seven women and four men returned partial verdicts as trial judge Mr Justice Goss imposed a reporting ban until their deliberations were complete.

On August 8 the jury – on its 15th day of deliberations – unanimously found her guilty of attempting to murder two infants by poisoning them with insulin.

Letby fought back tears in the middle of the dock after the verdicts were returned by the jury foreman.

She burst out crying as she left the courtroom with prison officers as relatives of the victims looked on from the public gallery.

Her mother Susan, 63, shielded her face as she wept on the opposite side of the public gallery and was comforted by husband John, 77, who later leaned forward with his head in his hands.

At the start of deliberations on the afternoon of August 11 the jury delivered verdicts on a further six counts.

Letby was found guilty of murdering four babies and attempting to murder two others.

She stared at the floor as the verdicts were returned but was tearful as she left the dock.

Her mother could be heard sobbing and saying “you can’t be serious” and “this can’t be right”.

On August 16 the jury convicted her on six more counts – three murders and three attempted murders – and cleared her of one count of attempted murder.

The grandmother of Child G, a baby girl, gasped as Letby was found guilty of the infant’s attempted murder.

Letby was not in the dock as the above verdicts were returned as she did not want to come up from the cells. She was earlier present when the jury resumed its deliberations at the start of the court day.

The morning of August 17 was her last appearance in the courtroom as she went on to tell her legal team that she did not wish to attend any more of the proceedings.

She was offered the opportunity of following her sentencing hearing next Monday via prison videolink but said she was not prepared to do that.

On Friday, after deliberating for 110 hours and 26 minutes – spread over 22 days – the jury said they could not reach verdicts on six remaining counts of attempted murder in relation to four infants.

In total, they found Letby guilty of seven counts of murder and seven counts of attempted murder in relation to six babies.

Prosecutors asked for 28 days to consider their position over whether to seek a retrial on the six outstanding counts.

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.

Only those cases highlighted as concerning medically would be investigated further, police added.

A court order prohibits reporting of the identities of the surviving and dead children who were the subject of the allegations.