prescription - Potassium Chloride. Professor, could you poison someone with Potassium Chloride and hope to get away with it?
Forsyth Oh, yes, it’s the most satisfactory of all poisons for a would-be murderer. Once injected, the victim will suffer a cardiac arrest, showing absolutely no sign of being poisoned.
Kersley So what led you to suspect that this was not a death by natural causes?
Forsyth The discovery of a deposit of Potassium Chloride on the rubber glove found on the floor of the Sherwoods’ kitchen.
Kersley And how much poison was discovered on the glove?
Forsyth One milligram, which is an amount consistent with checking that a hypodermic needle was working effectively.
Kersley Would you care to demonstrate to the jury exactly what you mean by that, Professor?
Forsyth Certainly. (
Pulls on a rubber glove and demonstrates to the audience
.) Just before injecting a patient, you press the plunger thus, to ensure that the liquid is flowing. (
He allows it to fly into the air, landing on his glove
.) As you observe, some droplets end up on the glove.
Kersley And this led you to believe that Mrs Sherwood had probably received an injection of Potassium Chloride just before her death?
Forsyth Yes, it did.
Kersley And could such an injection also have caused the bruising on her arm?
Forsyth Most certainly it could, especially if she had offered any resistance.
Kersley Professor, I should now like to ask you about the glass of wine found on the table by Mrs Sherwood’s side. Have you been able to analyse its contents?
Forsyth Yes I have, and they revealed large deposits of Temazepam - a particularly strong sedative, available only on prescription. There was enough left in the glass to have knocked out a heavyweight boxer.
Kersley Which would, had she taken it, have made injecting her all the more easy.
Barrington My Lord, I was accused by my learned friend of a plot worthy of
A Book at Bedtime
. Following Mr Kersley’s flight of fancy, once this trial is over can I assume he will be applying to become an investigative journalist with the
News of the World?
Judge We will leave the jury to decide which one they consider the better qualified for that job, Sir James. Carry on, please, Mr Kersley.
Kersley Professor, can you confirm that six ampoules of Potassium Chloride were collected by Ms Mitchell from a chemist in Wellingborough?
Forsyth Yes, I can. I studied the poison register and checked all six entries against the prescriptions collected by Miss Mitchell and they all tallied.
Kersley And as a leading authority on the subject, would you now tell the court how many ampoules of Potassium Chloride it would take to cause a fatal heart attack?
Forsyth (
hesitates
) Four ampoules would be certain to cause cardiac arrest, but a fifth would leave no hope of survival.
Kersley And how would the victim die, Professor?
Forsyth In great pain, before the heart finally gave out.
Kersley But surely the post-mortem would reveal strong traces of Potassium Chloride that would cause the examining doctor to become suspicious?
Forsyth Unfortunately not. A heart attack causes an unusual amount of Potassium to be released into the bloodstream, which would be regarded as quite normal by any doctor conducting a post-mortem.
Kersley And Mr Sherwood would have been aware of this?
Forsyth A first-year medical student would have been aware of it.
Kersley Professor, what would be your opinion of a doctor who took advantage of such specialised knowledge?
Forsyth It betrays the very principles of the Hippocratic Oath, ‘Whatever house I enter, there will I go for the benefit of the sick, refraining from all wrong doing.’ The meaning could not be clearer.
Kersley No more questions, My Lord.
Judge Sir James. Do you wish to cross-examine?
Barrington Thank you, My Lord. Dr Forsyth.
Forsyth Professor.
Barrington I do apologise, Professor. May I begin by congratulating you on such an illustrious career, detailed so