AN EXPERT ON HAIR.

Nothing could point more strongly to the guilt of Ross than satisfactory proof that hairs from the head of the murdered girl were found on a blanket in his private room. It becomes necessary, therefore, to examine Mr. Price’s evidence, to see whether it does establish this important fact. It will be seen by a reference to that evidence, that Mr. Price uses very guarded language. He “came to a conclusion” about certain things and he “formed the conclusion” about others, but he at no time definitely stated that the hairs taken from the blankets were from the same head as the hairs in the envelope. None the less, the fact cannot be blinked that the tendency of Mr. Price’s evidence was in that direction, or that in that direction lay the bent of his mind.

A word of caution as to expert evidence generally may, therefore, appropriately be given, and if a quotation from “Taylor on Evidence” is selected, no one who knows anything of the subject, will question the weight of the authority.

“Perhaps the testimony which least deserves credit with a jury,” says the author, “is that of skilled witnesses. These gentlemen are usually required to speak, not to facts, but to opinions; and when this is the case it is often quite surprising to see with what facility, and to what an extent, their views can be made to correspond with the wishes or the interests of the parties who call them. They do not, indeed, wilfully misrepresent what they think, but their judgments become so warped by regarding the subject in one point of view, that even when conscientiously disposed, they are incapable of forming an independent opinion. Being zealous partisans, their Belief becomes synonymous with Faith as defined by the Apostle, and it too often is but ‘the substance of things hoped for, the evidence of things not seen.’ To adopt the language of Lord Campbell, ‘skilled witnesses come with such a bias on their minds to support the cause in which they are embarked, that hardly any weight should be given to their evidence.’”

The first criticism of Mr. Price’s evidence is that he is not an expert on the subject, and indeed he made no pretence of being one. He knew nothing about the subject beforehand, and his experiments and reading were principally done after the event. For all he knows to the contrary, the pith of all hairs may be identical. He made one admission in the course of his cross-examination which absolutely destroyed the probative force of his evidence. In his post-factum observations he had examined hairs from several auburn heads, and he admitted that he had found some hair as like Alma Tirtschke’s as the hairs from the blankets. The “proof,” therefore, resulting from Mr. Price’s evidence may be reduced to an elementary syllogism as follows:—

It was said earlier that Mr. Price might, on the facts he deposed to, have been a powerful witness for the defence. Let us show how this is so. Suppose, having deposed to the examination of the two sets of hairs, exactly as given previously, he had been examined by Counsel for the Defence, and had answered in the following way, would not his answers have been fully justified by what he had already stated?:—

Defendant’s Counsel—Having examined the two sets of hair, are you of opinion they did not come from the same head?—I am.

Can you give reasons for your opinion?—I can, many.

What are they?—In the first place, the hair was not of the same average length, that from the head of the girl being, on the average, six inches longer than that from the blanket. In the next place, the hair from the blanket was of a light auburn colour, while the hair from the head was an auburn colour tending to red or a deep red. What is more important, the hairs from the two sets were not of the same diameter, and I cannot imagine why hair from the same head should differ in diameter. In the next place, in hair I have examined since, the frontal portion was quite red, and that from the back of the head quite dark, suggesting that where the hair is exposed, it lightens in colour, while in this case the hairs, which must have come from the back of the head, were actually lighter than those which came from nearer the front. In the next place, I found in my investigations hairs which were quite as like Alma Tirtschke’s as the hairs on the blanket, and though this does not prove that they were not Alma’s hairs, it prevents, by an elementary rule in scientific investigations, any deduction that they were. Lastly, it appears incredible to me, that if a girl of 13 were lying on a blanket for three hours she should lose 27 hairs—or rather that 27 of her hairs should still be remaining on the blankets at the expiration of a fortnight, during which the blankets had been removed to a distant suburb, and constantly handled.