Vivian Mahoney was a toxicologist who performed tests for toxic substances under the direction of Mr Ogg, but found nothing. Interviewed for the documentary Who Killed Dr Bogle & Mrs Chandler?, he revealed that the blood samples taken from both bodies had had a strange, purplish discolouration that he'd never seen before.

He also revealed that he'd only finished testing for possible toxins when he ran out of samples. He subsequently resigned and never worked again in forensic toxicology.