Lucy Letby, a 34-year-old nurse, was convicted of murdering seven infants and attempting to murder six others at Chester Hospital in Cheshire, England, between June 2015 and June 2016.

Her heinous actions have led to her being regarded as one of the most prolific child killers in UK history, resulting in a life sentence.

The investigation into Letby's conduct began in May 2017, prompted by concerns raised about her behavior in the neonatal unit.

During the public inquiry, Dr. Stephen Brearey, a consultant pediatrician, revealed that there were suspicious cases involving Letby that had not been reported prior to June 2015.

Brearey also suggested that Letby's harmful actions may have commenced even earlier than June 2015, challenging the established timeline of her criminal behavior.

The inquiry indicated that Letby likely murdered or assaulted more children than she was convicted of, raising serious concerns about the extent of her actions.

Dr. Ravi Jayaram testified that he witnessed Letby standing over an infant with a dislodged breathing tube, failing to intervene as the baby's oxygen levels declined.

Prosecutors attributed the infant deaths to the administration of excess milk, air, insulin, or fluid, highlighting the methods of harm used.

In her defense during the trial, Letby claimed she intended no harm and suggested that the deaths could be linked to plumbing issues in the hospital.

Brearey pointed out that the perception of normalcy within the neonatal unit had shifted due to an increase in unexplained events over the years.