The Thirlwall Inquiry is investigating how nurse Lucy Letby managed to continue her series of murders at the Countess of Chester Hospital's neonatal unit for over a year.

Despite growing concerns, Dr. Gibbs testified that doctors faced strong opposition from senior nurses when raising suspicions about Letby in early 2016.

Dr. Gibbs's concerns about Letby's involvement grew through late 2015 and into 2016 as he noticed an unsettling pattern of infant collapses and deaths.

Dr. Gibbs felt influenced by strong pushback from senior nurses who argued that suspicions against Letby were unfounded.

Letby's name first emerged as a 'common factor' in the unexplained collapses of three babies in June 2015, although initial suspicions of harm were dismissed.

In 2022, Letby was found guilty of attempting to murder Child F by poisoning him with insulin in August 2015, after previously murdering four newborns.

Concerns about Letby's involvement in the deaths of multiple infants were raised as early as July 2015, but Dr. John Gibbs, a senior doctor, did not suspect deliberate harm at that time.

Letby, now 34, has been sentenced to 15 whole-life orders after being convicted of murdering seven infants and attempting to murder seven others between June 2015 and June 2016.

The inquiry is set to continue until early 2024, with findings expected to be published by late autumn 2025.

Dr. Gibbs apologized to the parents of Letby's 14 victims during the inquiry, acknowledging their need for explanations rather than mere apologies.

In May 2016, Dr. Stephen Brearey informed hospital management of suspicions regarding Letby, but no immediate action was taken.

In April 2017, the hospital hired a barrister to evaluate the situation, which ultimately led to police involvement in May and Letby's arrest in July 2018.