Christina Edkins' killer Phillip Simelane threatened own mother
Phillip Simelane, the man who stabbed 16-year-old schoolgirl Christina Edkins to death on a Birmingham bus, had previously been in prison for threatening his own mother with a knife.
Christina was on her way to Leasowes High School in Halesowen for an exam when she was killed on 7 March - three months after Simelane had been released from jail.
West Midlands Police said they had been called to his mother's address in Walsall about 20 times.
She had contacted the force "for a number of issues, fighting with siblings, arguing with [her] and causing criminal damage" in the house, police said.
Simelane, now 23, served a jail sentence for the threats to his mother last year and had another conviction for violence.
'Unfair to speculate'
The force said it was now believed he was suffering from paranoid schizophrenia at the time he killed Christina, in the Edgbaston area of the city.
But when the teenager was attacked with "a normal kitchen knife" on the number nine bus near Five Ways, homeless and unemployed Simelane was not under "any kind of care plan", police said.
The force said it had "no further contact" with Simelane after December, when he was released from prison where he had been sent following a breach of licence conditions for a sentence he had served for interfering with a vehicle.
Agencies involved in managing Simelane before the attack are holding independent reviews to try to establish what support he had, with prison and mental health services involved, police said.
Supt Richard Baker said: "From what we know of Phillip Simelane as a result of Christina's murder (sic), he has only recently as a result of this been diagnosed with schizophrenia. There doesn't appear to be any historic diagnosis of this illness previously.
"I think it's probably unfair to speculate at this particular time what was or could or should have been done by the relevant agencies."
Christina, the youngest child of Jason and Kathleen and sister of Joanne, 24, and Ryan, 18, was a GCSE student.
Her family said she was "very much looking forward to" her school prom and had bought "a beautiful lilac dress" for the event, and it was their wish that she wore it on the day of her funeral.
The prom was dedicated to her and dozens of balloons of her favourite colour purple were released.
In a family statement released by her great-uncle Chris Melia, they spoke of their pride in her exam results - 11 subjects with grades from A* to C - along with "the pain that her ambition to study to be a nurse or midwife will be unfulfilled".
Mr Melia told the BBC when Christina's father called him on the day she was stabbed, he had to tell him three times before it "really went in for me that she was dead".
He added: "Certainly there should be answers as to how did this happen, and how is it going to be prevented from happening in the future?
"It was clearly identified that this guy had a severe problem."
The chief executive of mental health charity Sane, Marjorie Wallace, said there were opportunities at all stages from school onwards to have Simelane assessed and treated, "all of which appear to have been missed".
She said: "Over the last 10 years Simelane showed all the signs of mental illness, was violent towards his family, and had concerns raised about his mental health in prison.
"If society cannot cope with one disturbed young man, we should be concerned at the number of others in prison who may be released unconditionally in the same way."
Christina had left home on a normal Thursday at about 07:30 and boarded the bus on Broad Street. Simelane was already on it.
The teenager was attacked about five minutes later.
Simelane was homeless and had been on the bus for more than two and a half hours. At one stage a passenger had alerted the driver to a man sleeping upstairs.
Supt Baker said: "[Simelane had] asked the bus driver if he could stay on for a bit longer because he was cold and he wanted to try and get some sleep.
"We would express no criticism whatsoever towards the bus driver in this particular incident. Nobody could have foreseen what was coming."