‘We know that a dictaphone was supplied to Mr Ackroyd.
But no dictaphone has been found amongst his effects. So, if something was taken from the table – why should not that something be the dictaphone? But there were certain difficulties in the way. The attention of everyone was, of course, focused on the murdered man. I think anyone could have gone to the table unnoticed by the other people in the room. But a dictaphone has a certain bulk – it cannot be slipped casually into a pocket. There must have been a receptacle of some kind capable of holding it.
‘You see where I am arriving? The figure of the murderer is taking shape. A person who was on the scene straightaway, but who might not have been if the crime had been discovered the following morning. A person carrying a receptacle into which the dictaphone might be fitted ‘ I interrupted.
‘By why remove the dictaphone? What was the point?’ ‘You are like Mr Raymond. You take it for granted that what was heard at nine-thirty was Mr Ackroyd’s voice speaking into a dictaphone. But consider this useful invention for a little minute. You dictate into it, do you not?
And at some later time a secretary or a typist turns it on, and the voice speaks again.’ ‘You mean – ?’ I gasped.
Poirot nodded.
‘Yes, I meant that. At nine-thirty Mr Ackroyd was already dead. It was the dictaphone speaking – not the man.’ ‘And the murderer switched it on. Then he must have been in the room at that minute?’ ‘Possibly. But we must not exclude the likelihood of some mechanical device having been applied – something after the nature of a time lock, or even of a simple alarm clock.
But in that case we must add two qualifications to our imaginary portrait of the murderer. It must be someone who knew of Mr Ackroyd’s purchase of the dictaphone and also someone with the necessary mechanical knowledge.
‘I had got thus far in my own mind when we came to the footprints on the window ledge. Here there were three conclusions open to me. (1) They might really have been made by Ralph Paton. He had been at Fernly that night, and might have climbed into the study and found his uncle dead there. That was one hypothesis. (2) There was the possibility that the footmarks might have been made by somebody else who happened to have the same kind of studs in his shoes. But the inmates of the house had shoes soled with crepe rubber, and I declined to believe in the coincidence of someone from outside having the same kind of shoes as Ralph Paton wore. Charles Kent, as we know from the barmaid of the Dog and Whistle, had on a pair of boots “clean dropping off him.” (3) Those prints were made by someone deliberately trying to throw suspicion on Ralph Paton. To test this last conclusion, it was necessary to ascertain certain facts. One pair of Ralph’s shoes had been obtained from the Three Boars by the police. Neither Ralph nor anyone else could have worn them that evening, since they were downstairs being cleaned. According to the police theory, Ralph was wearing another pair of the same kind, and I found out that it was true that he had two pairs. Now for my theory to be proved correct it was necessary for the murderer to have worn Ralph’s shoes that evening – in which case Ralph must have been wearing yet a third pair of footwear of some kind. I could hardly suppose that he would bring three pairs of shoes all alike – the third pair of footwear were more likely to be boots. I got your sister to make inquiries on this point – laying some stress on the colour, in order – I admit it frankly – to obscure the real reason for my asking.
‘You know the result of her investigations. Ralph Paton had had a pair of boots with him. The first question I asked him when he came to my house yesterday morning was what he was wearing on his feet on the fatal night. He replied at once that he had worn boots – he was still wearing them, in fact – having nothing else to put on.