He looked at me with slightly raised eyebrows, and I continued:
“I know these people pretty intimately and I find it impossible to entertain the idea that any of them could have committed this callous, deliberate crime. At the moment, I realize circumstances seem to involve them in suspicion; but I am certain that there is some fallacy—that there are some facts which did not transpire at the inquest but which might be brought to the surface if you took the case in hand.”
“Why not let the police disinter those facts?”
“Because the police evidently suspect the members of the household and they will certainly pursue the obvious probabilities.”
“So should I, for that matter,” said he; “and in any case, we can’t prevent the police from bringing a charge if they are satisfied that they can support it. And your own experience will tell you that they will certainly not take a case into the Central Criminal Court unless they have enough evidence to make a conviction a virtual certainty. But I remind you, Mayfield, that they have got it all to do. There is grave suspicion in respect of a number of persons, but there is not, at present, a particle of positive evidence against any one person. It looks to me as if it might turn out to be a very elusive case.”
“Precisely,” said I. “That is why I am anxious that the actual perpetrator should be discovered. Until he is, all these people will be under suspicion, with the peril of a possible arrest constantly hanging over them. I might even say, ‘hanging over us’; for you, yourself, have included me in the group of possible suspects.”
He reflected for a few moments. At length he replied:
“You are quite right, Mayfield. Until the perpetrator of a crime is discovered and his guilt established, it is always possible for suspicion to rest upon the innocent and even for a miscarriage of justice to occur. In all cases it is most desirable that the crime should be brought home to the actual perpetrator without delay for that reason, to say nothing of the importance, on grounds of public policy, of exposing and punishing wrong-doers. You know these people and I do not. If you are sufficiently confident of their innocence to take the risk of associating yourself with the agencies of detection, I have no more to say on that point. I am quite willing to go into the case so far as I can, though, at present, I see no prospect of success.”
“It seems to you a difficult case, then?”
“Very. It is extraordinarily obscure and confused. Whoever poisoned that unfortunate man, seems to have managed most skilfully to confuse all the issues. Whatever may have been the medium through which the poison was given, that medium is associated equally with a number of different persons. If the medicine was the vehicle, then the responsibility is divided between Dimsdale, who prepared it, and the various persons who administered it. If the poison was mixed with the food, it may have been introduced by any of the persons who prepared it or had access to it on its passage from the kitchen to the patient’s bedroom. There is no one person of whom we can say that he or she had any special opportunity that others had not. And it is the same with the motive. No one had any really, adequate motive for killing Monkhouse; but all the possible suspects benefited by his death, though they were apparently not aware of it.”