A man accused of four murders over three days fantasised what it would be like to be fictional killer Freddy Krueger, the Old Bailey has been told.
Marie Harding was killed in Brighton on 15 September
Daniel Gonzalez, 25, from Woking, Surrey, told police he used to watch a lot of horror films at home.
The jury was told voices in his head told Gonzalez to act like the killer in the film, Nightmare On Elm Street.
He has denied murdering Jean and Derek Robinson and Kevin Molloy in London, and Marie Harding in Hove, East Sussex.
He has admitted manslaughter on the grounds of diminished responsibility, but this has not been accepted by the prosecution.
It alleges Gonzalez set out to murder at least 10 people in an area stretching from the south coast to London.
The court was told on Wednesday that following his arrest in September 2004, a note written by Gonzalez was discovered among property he left at the luggage deposit at King's Cross Station in London.
The note read: "I will be a serial killer. I am gonna make sure I get to London and kill some old bill as soon as I can...
"I will kill as many old bill as I can as best I can.
The Robinsons were killed in their own home on a secluded estate
"So when the death toll reaches 10 which is at one."
Prosecutor Richard Horwell said this referred to his ambition to reach double figures in his killing campaign.
He told jurors the central issue in the case was whether or not the defendant was suffering from psychotic symptoms, namely auditory hallucinations, at the time of the killings.
The prosecution did not accept this diagnosis, he said.
"The Crown's response will be that the defendant was in control and command of his actions... and that the defendant is, in law, a murderer.
"If the voices were drug-induced, their origin is not mental illness."
Trail of blood
The court heard Gonzalez had admitted the attempted murder of two people he attacked in September 2004.
There was no defence of diminished responsibility to attempted murder - only for murder, the prosecution explained.
The two he tried to kill were Peter King, 61, in Portscreek, Portsmouth, on 15 September and Koumis Constantino, in Hornsey, north London, on 17 September.
The court heard how Gonzalez attacked and killed retired paediatrician Derek Robinson, 75, and his wife Jean, 60, with a knife at their home in Highgate Hill, north London, on 17 September.
"Mr Robinson was stabbed in the face, neck and abdomen. Mrs Robinson was stabbed in the face, neck and chest. Both died," Mr Horwell told the jury.
Gonzalez was seen immediately after the attack by a decorator who had let himself into the property.
The jury was told he fled the house leaving a trail of blood, and was arrested several hours later at Tottenham Court Road underground station. The trial continues.