A man who had been found to be unfit to enter a plea to murdering a care worker in Bedfordshire has been convicted of killing her by a jury.
Kathleen Bainbridge, 58, of Luton, died on 24 August 2007 after being stabbed at the Abacus Nursing Home, Dunstable.
Stephen Flatt, 55, a resident of the home, was charged with her murder but was ruled unfit to enter a plea.
At a two-day trial of issue at Luton Crown Court, jurors unanimously decided that Flatt did kill her.
As well as killing Ms Bainbridge, of North Drift Way, Luton, Flatt also tried to kill her colleague, Barbara Hill.
Judge John Bevan QC raised questions about how a mentally ill man came to be placed in a residential care home, where he stabbed a care worker to death and tried to murder another.
"There are questions here which cry out for an answer for example what on earth Stephen Flatt was doing in plainly wholly unsuitable premises," he said.
"I want to know to what extent other inquiries are being taken and if they are not I would consider instituting an independent inquiry."
The evidence revealed that Flatt had a long history of mental illness and had been cared for in hospitals and institutions mainly in the St Albans area.
He was diagnosed with a bipolar disorder and was unable to care for himself in the community.
But in July 2007, it was decided that he was well enough to be moved to Abacus House in Prince's Street, Dunstable.
The privately-run home normally housed up to six residents who suffered from brain injuries, but who were not mentally impaired.
The staff had not been trained to deal with psychiatric or aggressive patients, and expressed their concerns about Flatt being moved there, said prosecutor Beverley Cripps.
Flatt himself said he was unhappy there and Mrs Bainbridge had told her husband that she was scared of him.
Five weeks after being admitted he suddenly and without saying a word got a knife from an open kitchen and stabbed Mrs Bainbridge twice, severing two arteries.
Flatt told police he thought there was something "wicked and evil" about Abacus House and that he should not have been there.
He was due to be sentenced at Luton Crown Court on Wednesday.