A nurse in the UK was found guilty on Friday of killing seven newborn babies and attempting to kill six more in the hospital's neonatal unit where she worked, news agency AFP reported. She has now become the UK's most prolific killer of children.  Lucy Letby, who is 33 years old, has been on trial since last October. She has been accused of causing harm to her young victims, who were either sick or born prematurely. It is alleged that she injected them with air, overfed them milk, and poisoned them with insulin. 


In a search of Lucy Letby's home, the police found paperwork from the hospital and a note that she had written by hand reading: "I am evil, I did this."


The jury at Manchester Crown Court in northern England made their decisions after thinking about it for 22 days.


Lucy Letby was taken into custody after several babies died at the neonatal unit of the Countess of Chester Hospital in northwest England from June 2015 to June 2016.


The prosecution said Lucy Letby was very clever and used ways to kill that were hard to detect. Lucy Letby had repetitively denied hurting the children.


"Lucy Letby was entrusted to protect some of the most vulnerable babies. Little did those working alongside her know that there was a murderer in their midst," Senior Crown Prosecutor Pascale Jones was quoted by AFP in its report. 


"Time and again, she harmed babies, in an environment which should have been safe for them and their families," the prosecutor added, calling the killings "a complete betrayal of the trust placed in her".


The court was told that Lucy Letby's coworkers became worried when they noticed that she was working when the babies suddenly became sick. Some of the babies were harmed right after their parents had left them in their cots.


Prosecutor Nick Johnson said that Lucy Letby tricked her colleagues into thinking that the series of deaths were just a series of unfortunate events.


Lucy Letby's last victims were two triplet boys, who were called babies O and P during the court proceedings.


Child O died soon after Lucy Letby came back from a vacation in Ibiza in June 2016. Child P passed away one day after their brother or sister. Lucy Letby allegedly tried to kill the third triplet, child Q, but the jury could not agree on whether she was guilty or not. 


Johnson said that by that time Lucy Letby was "completely out of control", adding that "she was in effect playing God".