Rico Savva later met friends with his clothes covered in blood and bloody fingermarks on his face. An Old Bailey court was told his claim that he had fought off a mugger was 'fictional'.
Savva later told psychiatrists he had taken LSD and suddenly cars seemed to have teeth and skeletons emerged from the ground to attack him. He said he fought back with a lump of wood.
The court heard he used the wood to batter to death Peggy Holmes, 63, who was a familiar figure in Brixton, south London, where she lived in a home. 'She was utterly harmless,' John Bevan, for the prosecution, said.
Savva, of Brixton, was seen with charms from a bracelet she had been wearing. He denied murder.