Toni Rudman's body was found near a builder's yard in Plumstead
A teenager on trial for murdering a complete stranger in south east London was "disturbingly calm" in the aftermath, a court has heard.
Ryan Backhouse, 19, is charged with murdering Toni Rudman on an industrial estate in Plumstead on 7 August 2010.
Miss Rudman died from multiple injuries with major damage to her head and neck.
Mr Backhouse admitted Miss Rudman's manslaughter at Woolwich Crown Court on Monday but denies murder on the grounds of diminished responsibility.
The court heard Mr Backhouse, of Woolwich, had spent the evening drinking beer and playing on a fruit machine.
He was captured on CCTV raining blows down on the 24-year-old, who he had never met before, and launching a flying kick as she crouched on the ground.
'Clear and focused'
One of the officers who arrested Mr Backhouse described to the court his mood when he was originally arrested on suspicion of grievous bodily harm.
Pc Shola Oladotun said: "He was very clear and focused - quite disturbingly calm."
He was later rearrested in custody after the victim died.
Asked by Mr Backhouse's QC, Owen Davies, if he expressed regret or any emotion, the officer said she remembered nothing like that.
On Monday the jury heard Mr Backhouse told officers after the killing: "I was hurting so I wanted to hurt someone."
The court heard the police asked him who the victim was, to which he answered: "I don't know. I have never seen her before. My girlfriend hurt me so I have hurt someone."
The trial continues.
