A neonatal nurse in a British hospital was found guilty Friday of murdering seven babies and trying to kill six others during a yearlong campaign of deception that saw her prey on the vulnerabilities of sick newborns and their anxious parents.

Following 22 days of deliberation, the jury at Manchester Crown Court convicted 33-year-old Lucy Letby of killing the babies, including two triplet boys, in the neonatal unit at the Countess of Chester Hospital in northwest England between June 2015 and June 2016. She will be sentenced on Monday.

“Parents were exposed to her morbid curiosity and her fake compassion,” said senior prosecutor Pascale Jones. “Too many of them returned home to empty baby rooms. Many surviving children live with permanent consequences of her assaults upon their lives.”

Her attacks, Jones said, were “a complete betrayal of the trust placed in her.”

Families of the victims said they will “forever be grateful” to jurors who since last October had to sit through 145 days of “grueling” evidence.

In a joint statement read outside court, they also expressed their gratitude to all those who came to give evidence during the trial, which they described as “extremely harrowing and distressing” to listen to.

“To lose a baby is a heart-breaking experience that no parent should ever have to go through, but to lose a baby or to have a baby harmed in these particular circumstances is unimaginable,” they said.

Letby’s motives remain unclear, but the scale of her crimes points to intricate planning.

She was accused of deliberately harming the babies in various ways, including by injecting air into their bloodstreams and administering air or milk into their stomachs via nasogastric tubes. She was also accused of poisoning infants by adding insulin to intravenous feeds and interfering with breathing tubes.

The British government launched an independent inquiry soon after the verdicts that will look into the wider circumstances around what happened at the hospital, including the handling of concerns raised by staff.

“This inquiry will seek to ensure the parents and families impacted get the answers they need,” Health Secretary Steve Barclay said. “I am determined their voices are heard, and they are involved in shaping the scope of the inquiry should they wish to do so.”

One of the senior doctors at the Countess of Chester Hospital told the BBC he had repeatedly tried to raise the alarm about Letby but hospital executives failed to investigate the allegations.

Dr Stephen Brearley, the lead doctor in the neonatal unit, said the hospital tried to silence doctors who complained about Letby and delayed calling the police.

The jury of seven women and four men deliberated for 22 days before reaching the verdict. One juror was excused well into deliberations for personal reasons, and the judge later gave the remaining 11 jurors the option of reaching a verdict with 10 people in agreement instead of a unanimous decision.

Letby was found guilty of the seven murders and of seven charges of attempted murder relating to six children. She was cleared of two charges of attempted murder and the jury could not reach a verdict on several others.

Some of the verdicts were announced in court earlier in the month, but the judge imposed a ban on reporting them until deliberations were complete.

During the lengthy trial, prosecutors said the hospital in 2015 started to experience a significant rise in the number of babies who were dying or suffering sudden deteriorations in their health for no apparent reason. Some suffered “serious catastrophic collapses” but survived after help from medical staff.

Letby was on duty in all the cases with prosecutors describing her as a “constant malevolent presence” in the neonatal unit when the children collapsed or died. They said the nurse harmed the babies in ways that did not leave much of a trace, and that she persuaded her colleagues that the collapses and deaths were normal.

Police launched an investigation into the baby deaths at the hospital in May 2017 and Letby was eventually charged in November 2020.

“The last thing we expected to find was a suspect responsible for these deaths and non-fatal collapses,” said the senior investigating officer, Detective Superintendent Paul Hughes.

“Turning up at the home of a family who have lost a baby, grieved for their loss and are trying to move on from that is difficult enough, but having to tell them that someone who was meant to be caring for their little one could ultimately be responsible for their death — is not an easy task,” he added.

Letby testified for 14 days, proclaiming her innocence. During the trial, the defense argued that she was a “hard-working, dedicated and caring” nurse who loved her job and that the infants’ sudden collapses and deaths could have been due to natural causes, or in combination with other factors such as staffing shortages at the hospital or failure by others to provide appropriate care.

Letby fought back tears on Aug. 8 as the jury found her guilty of two counts of attempted murder and burst out crying as she left the courtroom. She was present again three days later when she was convicted of four murders and another two attempted murders.

She declined to be in the courtroom as additional verdicts were announced Friday and has indicated to the court she does not wish to appear in court Monday, nor to follow the sentencing hearing via videolink.

A note police found at Letby’s home after she was first arrested in 2018 will now stand as a chilling confession.

“I don’t deserve to live,” she wrote on a green sticky note shown in court. “I killed them on purpose because I’m not good enough to care for them.”

“I am a horrible evil person,” she wrote. “I AM EVIL I DID THIS.”