Police faced a tough challenge in this investigation. It involved numerous members of staff and health care workers. It has taken time but police were always confident that Mr Chua was the killer.
Chua contaminated saline leaving other staff to unsuspectingly use the potentially lethal product.
According to the Guardian Monday Chua had a “malign intention to cause havoc" and he did just that.
His actions also led to suspicion between colleagues and hit patient confidence at Stepping Hill.