British nurse Lucy Letby, already convicted of killing 7 babies, found guilty in attempted killing

This undated photo shows nurse Lucy Letby. (Cheshire Constabulary via AP)

LONDON — A British neonatal nurse who is serving a life sentence for murdering seven babies and attempting to murder six others was convicted Tuesday of trying to kill another infant in her care.

Lucy Letby, 34, tried to kill a baby girl known as Child K in February 2016 at the Countess of Chester Hospital in northwestern England, a jury decided after a previous panel failed to reach a verdict on that count.

Letby, who testified that she never harmed a child, was found guilty in Manchester Crown Court last August of most of the crimes she was charged with that took place between June 2015 and June 2016 at the hospital's neonatal unit.

On Tuesday, a different jury convicted her of trying to murder a "very premature" baby girl by dislodging her breathing tube in the early hours of Feb. 17, 2016.

The parents of the baby gasped and cried as the verdict was read after three and a half hours of deliberations.

Letby showed no emotion.

Senior Prosecutor Nicola Wyn Williams said Letby removed the baby's breathing support and a doctor found her standing by doing nothing as the child struggled. She added that Letby removed the breathing tube two more times over the next few hours, "in an attempt to cover her tracks and suggest that the first dislodgment was accidental."

"These were the actions of a cold-blooded, calculated killer," she said. "Staff at the unit had to think the unthinkable -- that one of their own was deliberately harming and killing babies in their care."

Dr. Ravi Jayaram, a pediatrician at the hospital, told jurors he saw "no evidence" that Letby had done anything to help the baby as he walked in and saw her standing next to the newborn's incubator.

Letby told the jury of six women and six men she had no recollection of any such event. She denied she harmed Child K, and added that she had not committed any of the offenses she had been convicted of.

Letby is serving a life sentence with no chance of release -- the most severe punishment possible under British law, which does not allow the death penalty. Only three other women have received such a harsh sentence in the U.K.