Murder-accused nurse Lucy Letby would have needed a “Nostradamus-like ability to read the future” to target one of her alleged victims, a court has been told.

Letby, 33, is charged with trying to murder a twin baby boy by poisoning him with insulin a day after she allegedly murdered his newborn brother.

The prosecution suggest the neonatal nurse at the Countess of Chester Hospital contaminated two bags of nutritional feed given intravenously to Child F.

It is claimed she injected insulin into the first bag of total parenteral nutrition (TPN) during a night shift on the early hours of August 5 2015, which led to the plummeting of Child F’s blood sugar levels.

Letby is then said to have “cynically covered her tracks” as she contaminated a second stock maintenance bag to be used by an unsuspecting colleague after she clocked off.

Jurors at Manchester Crown Court have been told a blood sample taken when the second bag was in use later revealed a “biological fingerprint” which showed synthetic insulin was present – when none was prescribed.

Continuing his closing speech on Wednesday, June 28, Letby’s barrister Ben Myers KC said: “There is no evidence that Miss Letby interfered with any bag of TPN. None. Blink, ladies and gentlemen, and you will miss that point.

“We say there would be nothing quick about what the prosecution allege. It involves getting a syringe and the bag, drawing up the insulin and injecting it without arising suspicion and getting caught.

“The prosecution have suggested alternatively that the insulin was introduced when the bag was hanging. It still involves getting insulin from the fridge, having a syringe, getting it in the bag without detection when there is no reason for anyone to put insulin into a hanging TPN bag.

“It’s quite easy to make the allegations but it would be quite difficult to carry out.”

Mr Myers said the defendant did not have exclusive access to the TPN bags.

He said the evidence was that the overnight TPN bag – which last up to 48 hours – had to be replaced at noon later that day when a cannula inserted into Child F came out.

He added: “We say it’s incredible to maintain she is responsible for this. How can Miss Letby be held responsible for that second bag on any fair or logical basis? A high level of insulin in a bag that no-one could have foreseen would have been used which comes into play hours after she has left.”

He said the evidence indicated there were five stock maintenance bags at the time in the neonatal unit’s fridge.

Mr Myers said: “So even if somebody guessed that a maintenance bag may be needed in an unexpected way, they are not to know what bag would be taken. They would have to do the lot to make sure.

“You will keep in mind that stock bags are not stored in any particular order.

“It’s like a series of Russian dolls of improbability.

“There is no evidence that any other baby was affected at this time and you can be sure we would be told if there was.

“How on Earth is this a targeted attack unless Miss Letby had a Nostradamus-like ability to read the future? This is completely unrealistic.

“This is not party games – let’s get Letby. We are not here to invent explanations and ignore the evidence.

“Whatever happened to the TPN bag, or bags, there is no sensible way of claiming that Miss Letby could have been responsible for putting insulin in the second bag.

“That fundamentally undermines the accusation she put it in the first bag.”

Letby, from Hereford, denies the murders of seven babies and the attempted murders of 10 others between June 2015 and June 2016.

The trial continues on Thursday, June 29. The Standard will continue to provide live updates throughout the day.