A cagefighter accused of murdering his ex and attacking a teenage boy she was in an unlawful relationship with was too "emotionally spent" to talk when he was arrested, a court heard.
Paul Robson, 50, denies murdering Caroline Kayll, 47, at her home in Linton, Northumberland, in November.
He also denies severely injuring the 15-year-old who was at the property, Newcastle Crown Court has heard.
Mr Robson had prepared a statement for when he was interviewed by police.
Prosecutors said the ex-convict drove from Glasgow to confront Ms Kayll, who he had met when she worked at HMP Northumberland.
He is alleged to have inflicted severe head injuries on the teacher and strangled her at the home they had shared until shortly before the attack.
The prosecution claim he also attacked the youth with bladed objects, and sprayed both him and Ms Kayll with ammonia before taking their phones so they could not call for help.
The defendant claims it was the boy, who cannot be named for legal reasons, who killed his former partner.
When Mr Robson was arrested and interviewed by police, his solicitor handed detectives a prepared statement.
The statement said he was "emotionally spent" and "finding it very difficult to concentrate", adding: "I never intended to kill anyone."
It also said he was "not in a position to sensibly answer any questions", the court heard.
It continued: "I cannot believe Caroline is dead, I cannot believe she is gone.
"This is like a nightmare, like a bad dream.
"I am so tired and I am devastated."
In the statement, Mr Robson said he had been at Ms Kayll's house that night and they had argued before he was hit from behind, causing him to fall.
Jurors were told Robson was interviewed for two hours but did not reply.
He denies murder, attempted murder and blackmailing Ms Kayll over her relationship with the boy.
The trial continues on Monday.
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