This judgment "will not take away from the extreme pain, anger and distress that we have all felt," responded the families of the victims in a statement read on the steps of the court of Manchester (north) where it took nine months of trial and more than a month of deliberations to reach a verdict. "We may never know why this happened."

Lucy Letby is now considered the most prolific serial killer of children in modern UK history and police continue to review the records of thousands of patients in search of possible additional victims.

The 33-year-old, who said she was innocent, will be sentenced on Monday. She was not present in court on Friday.

Described as "cold, calculating, cruel and tenacious" by the prosecution, she worked in the intensive care unit of Countess of Chester Hospital in northwest England.

Between June 2015 and June 2016, seven premature babies died suddenly, for no obvious reason, sometimes within hours of each other.

This included injecting intravenous air into newborns, using their nasogastric tubes to send air, or an overdose of milk, into their stomachs.

Lucy Letby was the only medical staff still on duty during the sudden deterioration of the newborns, Judge James Goss said.

Faced with the shock of the case and questions about the response of the health services, the government has ordered the launch of an independent investigation to try to learn from it.

"Morbid curiosity"

The trial began on 10 October in Manchester. Parents testified, sometimes in tears.

One mother recounted how, returning to bring milk to one of her premature twins in August 2015, she heard him screaming and discovered he had blood around his mouth. She had been reassured by Lucy Letby.

According to the prosecution, the nurse had just pushed medical equipment down the tiny baby's throat, and had also injected him with air. He died a few hours later, after losing a quarter of his blood.

"The parents were exposed to his morbid curiosity and false compassion," prosecutor Pascale Jones said after the ruling. Her actions "represent a complete betrayal of the trust placed in her".

The prosecutor's office said Lucy Letby attacked babies after their parents left, when the nurse in charge moved away, or at night when she was alone. She then sometimes joined in collective efforts to save newborns, or even assisted desperate parents.

Alerts ignored?

Among the victims were triplets, two of whom died 24 hours apart after returning from vacation in June 2016. The third was spared after his parents begged him to be transferred to another hospital.

At that time, having killed without attracting attention, she had become "uncontrollable", said the prosecutor. "She thought she was God."

"I don't deserve to live. I killed them on purpose because I'm not good enough to take care of them. I'm a horrible person," the nurse wrote on a post-it note found at her home in 2018. In other documents, however, she maintained her innocence.

His lawyer Ben Myers argued that the neonatal ward had in 2015-2016 "welcomed more babies than normal, with greater care needs", and had "failed" to meet them.

He had claimed that incompetent doctors had blamed him but hospital services are now accused in a BBC investigation of covering the case despite warnings.

Transferred in June 2016 to an administrative department, arrested for the first time in 2018, then in 2019, Lucy Letby was finally incarcerated in November 2020. Police continue to investigate other periods of her career, including when she worked in a Liverpool hospital.

© 2023 AFP