Ordering him to be detained indefinitely in a secure psychiatric unit, Mrs Justice Thirwell, expressed deep concern that Simelane had been on the streets without any supervision at the time of the killing. She said: "At the time you attacked Christina you were suffering from a serious mental illness. Your mental function was wholly abnormal as a result of your mental illness. That is why you killed Christina - in your deluded state you thought she was a danger to you. It is difficult to understand how it came about that in December 2012 someone with your level of illness should have been sleeping rough with no one to look after you. The judge said: "On at least two occasions an experienced specialist registrar in psychiatry insisted you needed in-patient treatment. It was not made available to you. She added: "The terrible reality is that Christina was the person who happened to be on the bus on the day you were overwhelmed by your illness." An investigation has now been launched by Birmingham and Solihull Mental Health Trust to determine if more could have been done to prevent the tragedy. Christine's parents, Jason and Kathleen Edkins and her brother and sister, Ryan and Joanne were in court to hear Simelane admit to the killing. In a statement the family said: "The loss of a child is the worst thing that can happen, made even more grievous by such a senseless crime." They added: "The questions we now ask as a family are: 'when this man was discharged from prison on 13 December 2012, why was the recommendation made a few weeks earlier by mental health experts that he be supervised after release whilst adjusting to life back in the community not followed up? A child going to school in the morning on the bus should be safe in this country. In terms of how was he ever allowed to be wandering around, then there's a big question mark. Born in southern Africa, Simelane came to Walsall in the West Midlands with his mother and siblings when he was aged nine. He suffered from a range of mental health issued from his mid-teens and in 2007 received a reprimand for possessing a knife. Two years later he was cautioned for an offence of battery and was given a conditional discharge for criminal damage last year. Last July he was jailed for 26 weeks after threatening his mother with a knife and was released in October. A week later he was jailed again after being accused of trying to break into a car. In a statement, a spokesman for the Trust said: "Phillip Simelane had previously been in receipt of care from a number of healthcare providers over a period of years. Our Trust's involvement was in the form of prison-based mental health assessments during a prison term for an unrelated offence in 2012. What is clear, is that there are lessons to be learned for us and others involved in the care of Phillip Simelane to prevent such a tragedy happening again in the future. As a Trust we are currently leading an external review, commissioned by Birmingham Cross City Clinical Commissioning Group, on behalf of all the parties involved and intend to report on our findings in December 2013.