Upon the first part I have already, in the course of the trial, anticipated almost everything which relates to the evidence of Brown and Ainslie; I should therefore be ashamed to trouble you with more on that subject. I do not say that their being themselves accused of the crime in question should be a ground for totally rejecting their testimony, which the Court, proceeding on the present law and practice of Scotland, has allowed to be received. But this I will with confidence maintain, that the evidence of persons who, in the very outset of their testimony, confess the most enormous crimes, and thereby cover themselves with infamy as completely in the eye of reason as if they were convicted by sentence of a jury, can in no case be entitled to much credit, and when standing by itself is deserving of none at all.
But it is not on this alone that I impeach the testimony of these bad men; they stand in a situation different, very different, indeed, from other witnesses of that description--a situation to which I again entreat your best attention.
When Ainslie was first examined before the Sheriff, and for a long time afterwards, he persisted in maintaining the innocence of Mr. Brodie; nor was it till he learned that Brodie was apprehended, and till he was informed that to criminate him was the only means of saving his own life, that he uttered a syllable tending to infer the guilt of my client. This we offered to prove in the course of the trial, but a proof was refused by the Court.
The first testimony, therefore, which he gives in the matter is deliberately false. Is his after-information, or the evidence he has given this night, the better to be believed that it was wrung from him by the fear of death, or brought out of him by the hopes of life? It is vain to say that there is no proof that such means were used with him. There is real evidence that under these impressions he must have been when he delated Mr. Brodie. Well did he know that Mr. Brodie, from his unhappy connection with him and his associates, was suspected of being accessory to their guilt. He was not so blind as not to see that to the public prosecutor, whose duty it ever is to choose from various associates those whose situations make them the most striking examples of public justice, to accuse and convict such a person as Mr. Brodie was effectually to secure his own life.