A paranoid schizophrenic accused of murdering a Birmingham detective had not been taking his medication for "months or possibly years" prior to the killing, a court heard yesterday.
Glaister Earl Butler had become adept at tricking those responsible for his care in the community into thinking he was taking pills prescribed to stabilise his mental illness, Birmingham Crown Court was told.
But when police searched his home following the death of Detective Constable Michael Swindells, they found a " substantial amount" of un-opened medicine bottles.
Det Con Swindells was stabbed through the heart as he tried to arrest Butler on a canal towpath beneath Birmingham's Spaghetti Junction on May 21 last year.
The plain-clothed officer, who was not wearing body armour, had become involved in the pursuit after answering calls for assistance from colleagues sent to Nechells after Butler allegedly threatened a council carpenter with a knife.
Butler (49), of Long Acre, Nechells, denies murder but has admitted manslaughter on the grounds of diminished responsibility.
Timothy Raggatt QC, prosecuting, told the jury Butler's "underlying" mental health at the time of the killing was central to the case and they had to decide whether or not it had produced an abnormality of mind so substantial it had driven him to kill.
"The fact that someone has a mental illness, even quite a severe one, does not of itself give rise to the defence (of diminished responsibility)," he said.
"He was sufficiently in charge of his mind, we suggest, for you to certainly consider that he is fully responsible and culpable for what he did."
He told the jury: "This man unlawfully killed Mr Swindells by a plainly directed, deadly thrust of a knife."
Butler had suffered with paranoid schizophrenia intermittently for between 15 and 20 years and had been treated in hospital, sometimes against his will, on more than one occasion, Mr Raggatt said.
He was allowed back into the community in October 2001 under "careful and thorough medical supervision" and had been prescribed medication to stabilise his condition.
But, the court heard, he had stopped taking them.
Health professionals who visited Butler in the weeks leading up to the killing had had no cause for concern despite the fact he had taken up martial arts and had stabbed at a door at his flat, the court heard.
Mr Raggatt noted: "This man, although with an underlying mental illness, was able to convince those who had charge of him that he was indeed doing as he should when he plainly was not."
He said Butler had fled onto the Birmingham & Fazeley Canal when uniformed officers tried to detain him.
He slashed out with a knife at a police dog and another police officer who chased after him. Butler refused to stop and ran off.
Mr Raggatt said Det Con Swindells joined the chase and called for Butler to stop and to drop his weapon. He said the detective dodged one blow but was unable to avoid the fatal blow. The trial continues.