Such as the evidence was, Butler did little to shake it in cross-examination. His questions were many of them skilful and pointed, but on more than one occasion the judge intervened to save him from the danger common to all amateur cross-examiners, of not knowing when to stop. He was most successful in dealing with the medical witnesses. Butler had explained the bloodstains on his clothes as smears that had come from scratches on his hands, caused by contact with bushes. This explanation the medical gentlemen with good reason rejected. But they went further, and said that these stains might well have been caused by the spurting and spraying of blood on to the murderer as he struck his victims. Butler was able to show by the position of the bloodstains on the clothes that such an explanation was open to considerable doubt.

Butler's speech in his defence lasted six hours, and was a creditable performance. Its arrangement is somewhat confused and repetitious, some points are over-elaborated, but on the whole he deals very successfully with most of the evidence given against him and exposes the unquestionable weakness of the Crown case. At the outset he declared that he had taken his innocence for his defence. "I was not willing," he said, "to leave my life in the hands of a stranger. I was willing to incur all the disadvantages which the knowledge of the law might bring upon me. I was willing, also, to enter on this case without any experience whatever of that peculiarly acquired art of cross-examination. I fear I have done wrong. If I had had the assistance of able counsel, much more light would have been thrown on this case than has been." As we have seen, Butler enjoyed throughout his trial the informal assistance of three of the most able counsel in New Zealand, so that this heroic attitude of conscious innocence braving all dangers loses most of its force. Without such assistance his danger might have been very real.

A great deal of the evidence as to his conduct and demeanour at the time of the murder Butler met by acknowledging that it was he who had broken into Mr. Stamper's house on the Saturday morning, burgled it and set it on fire. His consciousness of guilt in this respect was, he said, quite sufficient to account for anything strange or furtive in his manner at that time. He was already known to the police; meeting Bain on the Saturday night, he felt more than ever sure that he was susspected{sic} of the robbery at Mr. Stamper's; he therefore decided to leave Dunedin as soon as possible. That night, he said, he spent wandering about the streets half drunk, taking occasional shelter from the pouring rain, until six o'clock on the Sunday morning, when he went to the Scotia Hotel. A more detailed account of his movements on the night of the Dewars' murder he did not, or would not, give.

When he comes to the facts of the murder and his theories as to the nature and motive of the crime—theories which he developed at rather unnecessary length for the purpose of his own defence—his speech is interesting. It will be recollected that on the discovery of the murder, a knife was found on the grass outside the house. This knife was not the property of the Dewars. In Butler's speech he emphasised the opinion that this knife had been brought there by the murderer: "Horrible though it may be, my conclusion is that he brought it with the intention of cutting the throats of his victims, and that, finding they lay in rather an untoward position, he changed his mind, and, having carried out the object with which he entered the house, left the knife and, going back, brought the axe with which he effected his purpose. What was the purpose of the murderer? Was it the robbery of Dewar's paltry wages? Was it the act of a tiger broken loose on the community? An act of pure wanton devilry? or was there some more reasonable explanation of this most atrocious crime?"

Butler rejected altogether the theory of ordinary theft. No thief of ambitious views, he said, would pitch upon the house of a poor journeyman butcher. The killing of the family appeared to him to be the motive: "an enemy hath done this." The murderer seems to have had a knowledge of the premises; he enters the house and does his work swiftly and promptly, and is gone. "We cannot know," Butler continues, "all the passages in the lives of the murdered man or woman. What can we know of the hundred spites and jealousies or other causes of malice which might have caused the crime? If you say some obscure quarrel, some spite or jealousy is not likely to have been the cause of so dreadful a murder, you cannot revert to the robbery theory without admitting a motive much weaker in all its utter needlessness and vagueness. The prominent feature of the murder, indeed the only feature, is its ruthless, unrelenting, determined vindictiveness. Every blow seemed to say, 'You shall die you shall not live.'"

Whether Butler were the murderer of the Dewars or not, the theory that represented them as having been killed for the purpose of robbery has its weak side all the weaker if Butler, a practical and ambitious criminal, were the guilty man.

In 1882, two years after Butler's trial, there appeared in a New Zealand newspaper, Society, published in Christchurch, a series of Prison "Portraits," written evidently by one who had himself undergone a term of imprisonment. One of the "Portraits" was devoted to an account of Butler. The writer had known Butler in prison. According to the story told him by Butler, the latter had arrived in Dunedin with a quantity of jewellery he had stolen in Australia. This jewellery he entrusted to a young woman for safe keeping. After serving his first term of two years' imprisonment in Dunedin, Butler found on his release that the young woman had married a man of the name of Dewar. Butler went to Mrs. Dewar and asked for the return of his jewellery; she refused to give it up. On the night of the murder he called at the house in Cumberland Street and made a last appeal to her, but in vain. He determined on revenge. During his visit to Mrs. Dewar he had had an opportunity of seeing the axe and observing the best way to break into the house. He watched the husband's return, and decided to kill him as well as his wife on the chance of obtaining his week's wages. With the help of the knife which he had found in the backyard of a hotel he opened the window. The husband he killed in his sleep, the woman waked with the first blow he struck her. He found the jewellery in a drawer rolled up in a pair of stockings. He afterwards hid it in a well-marked spot some half-hour before his arrest.

A few years after its appearance in Society, this account of Butler was reproduced in an Auckland newspaper. Bain, the detective, wrote a letter questioning the truth of the writer's statements. He pointed out that when Butler first came to Dunedin he had been at liberty only a fortnight before serving his first term of imprisonment, very little time in which to make the acquaintance of a woman and dispose of the stolen jewellery. He asked why, if Butler had hidden the jewellery just before his arrest, he had not also hidden the opera-glasses which he had stolen from Mr. Stamper's house. Neither of these comments is very convincing. A fortnight seems time enough in which a man of Butler's character might get to know a woman and dispose of some jewellery; while, if Butler were the murderer of Mr. Dewar as well as the burglar who had broken into Stamper's house, it was part of his plan to acknowledge himself guilty of the latter crime and use it to justify his movements before and after the murder. Bain is more convincing when he states at the conclusion of his letter that he had known Mrs. Dewar from childhood as a "thoroughly good and true woman," who, as far as he knew, had never in her life had any acquaintance with Butler.

At the same time, the account given by Butler's fellow-prisoner, in which the conduct of the murdered woman is represented as constituting the provocation for the subsequent crime, explains one peculiar circumstance in connection with the tragedy, the selection of this journeyman butcher and his wife as the victims of the murderer. It explains the theory, urged so persistently by Butler in his speech to the jury, that the crime was the work of an enemy of the Dewars, the outcome of some hidden spite, or obscure quarrel; it explains the apparent ferocity of the murder, and the improbability of a practical thief selecting such an unprofitable couple as his prey. The rummaged chest of drawers and the fact that some trifling articles of jewellery were left untouched on the top of them, are consistent with an eager search by the murderer for some particular object. Against this theory of revenge is the fact that Butler was a malignant ruffian and liar in any case, that, having realised very little in cash by the burglary at Stamper's house, he would not be particular as to where he might get a few shillings more, that he had threatened to do a tigerish deed, and that it is characteristic of his vanity to try to impute to his crime a higher motive than mere greed or necessity.

Butler showed himself not averse to speaking of the murder in Cumberland Street to at least one of those, with whom he came in contact in his later years. After he had left New Zealand and returned to Australia, he was walking in a street in Melbourne with a friend when they passed a lady dressed in black, carrying a baby in her arms. The baby looked at the two men and laughed. Butler frowned and walked rapidly away. His companion chaffed him, and asked whether it was the widow or the baby that he was afraid of. Butler was silent, but after a time asked his companion to come into some gardens and sit down on one of the seats, as he had something serious to say to him. For a while Butler sat silent. Then he asked the other if he had ever been in Dunedin. "Yes," was the reply. "Look here," said Butler, "you are the only man I ever made any kind of confidant of. You are a good scholar, though I could teach you a lot." After this gracious compliment he went on: "I was once tried in Dunedin on the charge of killing a man, woman and child, and although innocent, the crime was nearly brought home to me. It was my own ability that pulled me through. Had I employed a professional advocate, I should not have been here to-day talking to you." After describing the murder, Butler said: "Trying to fire the house was unnecessary, and killing the baby was unnecessary and cruel. I respect no man's life, for no man respects mine. A lot of men I have never injured have tried to put a rope round my neck more than once. I hate society in general, and one or two individuals in particular. The man who did that murder in Dunedin has, if anything, my sympathy, but it seems to me he need not have killed that child." His companion was about to speak. Butler stopped him. "Now, don't ever ask me such a silly question as that," he said. "What?" asked his friend. "You were about to ask me if I did that deed," replied Butler, "and you know perfectly well that, guilty or innocent, that question would only be answered in one way." "I was about to ask nothing of the kind," said the other, "for you have already told me that you were innocent." "Good!" said Butler, "then let that be the end of the subject, and never refer to it again, except, perhaps, in your own mind, when you can, if you like, remember that I said the killing of the child was unnecessary and cruel."