He had murder in mind, the ultimate revenge on one prostitute who had hospitalised him. Instead he slaughtered another who had done him no wrong.

His seasoned barrister had never experienced a case like it and even the judge did not wish him hanged.

Evidence Henry Haynes had slashed Mary McGowan's neck was irrefutable.

The only issue for jurors to decide - and by the standards of Victorian justice they were a long time doing so - was whether the otherwise peaceful, religious and sober soldier had become temporarily deranged.

Fellow regimental tailor Robert Callender convinced he was - and the cause lay thousands of miles away.

Haynes was a private in the 9th Regiment of Foot serving in America where he seduced a local girl who bore him a child. To all accounts he could not forgive himself, so much that when they were ordered back to barracks in Aldershot, he was a much changed man who refused to talk about his disgrace.

Barracks in Aldershot as featured in an old postcard.

Barracks in Aldershot as featured in an old postcard.

Not only did he take to drink but he sought out prostitutes, one of whom Margaret Cheltenham had apparently passed on a sexual disease.

And in his mind, she deserved to die.

"I often observed something peculiar about him," Callender revealed. "He was not the same man that had gone to America. Since he left there he does not appear properly in his senses."

Of his drinking bouts, Callender remarked: "He could not take so much as another man without showing it. It did not altogether make him tipsy but it made him do and say things he otherwise would not do."

He made his observations when called as a prime prosecution witness when Haynes, 21, stood trial at Hampshire Assizes, charged with the hideous murder of the prostitute in a notorious den of iniquity.

The two privates had flouted military discipline and had been confined to barracks but shortly before 10am on March 6, 1858, they broke out and went directly to the seedy London Tavern.

"It was one of those low houses to be found in the neighbourhood of the barracks where equally low women were in the habit of resorting," prosecutor Mr Cole said of the infamous premises.

Dressed in uniform, the men were a magnet for two sex for sale women and having downed glasses of the local rocket fuel, Callender escorted Emma Turner to one bedroom, and Haynes eagerly climbed the stairs with McGowan who was nicknamed 'Polly.'

Winchester Gaol

Winchester Gaol

After some time, the men prepared to leave but Haynes causally remarked to Turner: "Emma, I have left something in the other room."

Within seconds there was a piercing scream. Another prostitute Charlotte Davis rushed into McGowan's room at the very moment she slumped to her knees by the window as Haynes removed his hand clasping her throat.

It contained a razor.

Without saying a word, he nonchalently walked to the table, put the shaver into its case, and strolled out. McGowan lay on the floor and with blood gushing from the neck wound, expired within seconds.

Haynes meekly surrendered to the military train as the army police were termed but when questioned made a startling confession. It was not her he had intended to kill. It was Cheltenham who had confined him to hospital.

Charged with murder, he appeared before Baron Bramwell when his trial opened on March 16, with the Crown urging the jury to believe it had not been a spontaneous act but carried out with premeditation.

Mr Cole, prosecuting, submitted: "There is certainly one curious fact and that is he broke out of the barracks and carried with him a razor, as he admitted, to murder another girl but which in the end proved to be the means for the destruction of the life of the unfortunate deceased.

"I do not know what possible defence can be set up. So far as we can ascertain, there is nothing which affected his mind, and if the plea of insanity is put up, I am sure you will require it to be clearly and satisfactorily proved before you can relieve the prisoner from the consequences of his atrocious act."

Callender told the court how he had confronted his comrade when he saw McGowan lying on the floor bathed in blood.

"Why in the name of God did you do it?" But Haynes looking him straight in the face, could only reply: "Is she hurt, is she hurt?"

Callender conceded his friend had appeared to be acting normally that morning before "something came over him."

Under cross-examination, he gave an insight into his change of character from having to leave the woman and child behind. He refused to talk about it on the way home but he later "lamented very much at had taken place with the young woman and did not appear to be the man he was before."

Baron Bramwell.

Baron Bramwell.

Turner described his face as white as death as she tried comforting McGowan.

"She was on her knees, blood running from her neck, gasping 'The law have mercy on my soul.' He was absent, when I went to get some water, five minutes. I did not observe anything peculiar in his manner."

But in a postscript she described how Haynes had kissed her after she had died, asking, 'Polly, how did you get on?"

Sgt Travenor, in charge of the military train who relieved Haynes of his belt and bayonet on arrest, questioned him about the motive.

"He said, 'Poor girl, she never did me any harm, nor have I done her any harm, she never spoke to her, nor I to her. The devil made me do it. I intended to murder Margaret Cheltenham. Through her I was compelled to go to hospital and I was determined to be the death of her."

The prosecution having closed their case, Mr Edwards then addressed the jury for the defence. The principal facts uncontested, he urged the jury to acquit Haynes on the grounds of insanity.

"Whatever view you take, it is certainly one of the most mysterious I have ever heard of. The allegation is that he intended to murder Cheltenham but it appears the men went directly to this miserable place and did not inquire about her at all, did not express any word about her or any intention of searching for her. When you come to look for such malice, such provocation as to find him guilty, the case is an inextricable mystery.

"People do not murder without some intent. People do not commit a murder for the sake of committing a murder. In all your lives, in all your readings, have you ever heard of a man committing a murder without some object, some motive, some provocation? The very fact of committing a murder without a motive - and there are very many notable instances of it - is proof that at the time he was labouring under some insanity, for no human being in his right mind would commit murder and take away the life of another without some motive."

The seduction of the girl who had a child by him, had evidently preyed upon his mind.

"People might laugh at this and say such a thing is insufficient to account for the loss of a man's reason. But who can fathom the mysteries of the human mind. Circumstances less trifling have known to prey on a man's mind until that mind has become deceased and reason has left her seat. I therefore ask you that at the time this dreadful act was committed, he was in an unnatural state of mind, clearly beside himself and not knowing what he was doing."

Following a detailed summing up from the judge, Baron Bramwell, the jurors retired.

Spencer Horatio Walpole

Spencer Horatio Walpole

Unlike many cases of that period which invariably lasted a few minutes, if not seconds, their deliberations were at length. Two and a half hours had in fact elapsed before they returned to court, only to ask the judge for further clarification about the borders of murder and insanity.

Once more, the jury consulted but this time without leaving their seats, they returned their verdict - guilty.

The judge however was remarkably open in his sympathy, refusing to castigate Haynes but stressing the law was the law and he had to perform his duty in sentencing him to death.

However given the option, he would have spared him in favour of life imprisonment.

"I cannot but feel sorry for you. You have a good character and there appears to be regret for what you have done. I feel certain you would not do this again but without saying anything to pain you, this sentence will come into effect, and in order to make you believe that is true, it is my duty to tell you that you have been found guilty of a very cruel and bad act.

"You went out no doubt to commit some mischief, from taking that weapon with you. The unfortunate woman came into your way and under a miserable impulse of ferocity, you took her life. You cannot be spared."

Haynes then left the dock with a firm step but it was noticed by both counsel that deliberately or accidentally the judge had omitted the final prayer - that of 'May the Lord have mercy on your soul.'

A petition for clemency was swiftly launched, endorsed by the clergy, gentry, doctors and hundreds of Wintonians. Letters were also sent to the High Sheriff of Hampshire from his commanding officer and comrades. Even jurors pleaded for mercy. All the testimonials maintaining he had been mentally unwell and could not be held totally responsible for his actions.

The High Sheriff promised to personally deliver them to the Home Secretary Spencer Walpole, a celebrated barrister, who as custom demanded consulted Baron Bramwell.

Alas, all it seemed in vain. Time passed, the gallows were erected and the executioner took his lodgings in the city but less than two days before his public hanging outside Winchester Prison gates, a Home Office commissioner arrived with the declaration his life was being spared.

Moreover his sentence was not going to be commutted to life imprisonment, instead he would be transported to Australia for life.

Possibly the last killer to do so.