HIS face contorted in horror, the master-gunner ran across the parade ground and flinging himself in front of his bewildered superior officer, implored: "For God's sake, preserve me. There has been awful work down there, gentlemen. Do go down."

Thrusting his watch, an envelope and money towards him, William Whitworth gasped: "He used me shamefully and has held a pistol at my head and swore he would shoot me if I did not cut my throat."

To underline his ordeal, he pulled down his coat collar to reveal his throat, cut and bloody, and then ran off to burst into the mess room.

Sergeant John Daish and two other soldiers from the Isle of Wight Artillery were immediately directed to search his quarters.

At the door they were met by Robert Hoel, chief boatman at the Sandown Coastguard Station, who recounted a bizarre conversation with the unhinged Whitworth only minutes earlier.

"What's the matter?" he pleaded.

"Oh, horrid," Whitworth shrieked. "They have murdered my six children."

"Nonsense," Hoel cajoled him.

"Yes, they have," he insisted. "I have been watching these two men two or three nights and there was a man standing down there with a pistol in each hand. And they are all dead – my poor wife and all my children."

Then, to his horror, Hoel saw his bloodstained collar.

"I am going to the barracks but I will see you when I come down again," the increasingly alarmed boatman told him before running to his quarters where he met the three soldiers.

Fearfully pushing open the front door, they saw a bloodstained razor on the floor and an ominous trail leading to the bedrooms.

A naval cutlass lying on the carpet in one glinted from what light had pierced the shutters.

Pulling them back, the captain recoiled at seeing the mutilated bodies of Whitworth's wife and three of his children. In the other they discovered his three other children, equally disfigured.

The oldest was 12, the youngest a mere 12 months. Five had their throats slashed, small pools of blood on the ground and first floors and their clothing to suggest they may have survived the initial onslaught before being overwhelmed. The other had been suffocated by a pillow after fighting tenaciously for her life.

It could have been worse. Thankfully, their fourth son was away at the time and had escaped the massacre.

Whitworth had been transferred to Sandown Fort in July 1859, and his family occupied a two storied, somewhat dilapidated cottage on the left hand side of the small military base. His duties were light and principally connected with the running of the store.

He and his wife, Martha, were uniformly quiet and reserved, keeping themselves very much to themselves and adverse to gossip. Whitworth was perceived as being somewhat odd, not only the consequence of a head injury sustained in service but he conveyed a grudge against engineer officers who – he told his commanding officer – were under his power by reason of forged documents.

Though this was strictly a breach of military regulations, he declined to take action against the gunner, knowing the tendency of veteran soldiers, especially in the lower ranks, to adopt that level of conduct.

Though Whitworth did his work without fuss, he had become increasingly anxious to ensure he remained at the fort during the nine months he had left to serve before his discharge. Bloodstained letters to his commanding officer found on the ground floor betrayed his vexation.

News of the unparalleled tragedy quickly spread so much so that the local press printed a special edition and excited gossip suggested that with all the ammunition at his disposal he intended to blow up the fort.

All this time, Whitworth, recovering from the neck wound inflicted with an open razor recovered from his quarters, was confined to the infirmary under heavy guard. Occasionally he spoke of his wife in affectionate and touching terms, lauding her as a good wife and mother. Sometimes he alluded to his children.

The following day, May 19, 1860, an inquest jury endured the wretched task of accompanying the coroner, Mr F Blake, to view the bodies of the deceased, many leaving the scene in abundant tears.

As medical evidence revealed the extent of injuries, proceedings had to be temporarily adjourned after one passed out.

The evidence complete, Blake directed jurors they could not consider the question of his state of mind and their sole duty was to say whether they believed he was guilty or innocent of their deaths.

Wilful murder was their unanimous verdict, and under the coroner's warrant, his case was transferred to the Hampshire Assizes. But would he attend? Indeed for some time there was considerable doubt he would recover.

Physically he had when he appeared before Mr Justice Channell on July 17.

Mentally he had not, so diminished in his reasoning that he continually stared about him, uttered a series of incoherent observations and made out he was eating something.

The proceedings were governed by a statement from Dr Lyford who had examined Whitworth as soon as he had been remanded to Winchester Prison.

In a preliminary discussion attended by only prosecution and defence barristers, the judge asked the doctor: "Do you consider him to be in a fit state to understand the pleading of the indictment?"

He replied: "Decidedly not."

After the jury had been sworn, the judge addressed them on its implications.

"Gentlemen, you are to try whether this unhappy man placed at the bar is in a fit state to understand the proceedings that are about to be taken against him, whether he is in a fit state to plead to the indictment against him. I shall call before you the surgeon of the gaol and after what you have heard what he has to state, it will be for you to say whether or not he is in a fit state to plead to the indictment."

Dr Lyford declared: "His mind at the present moment is almost in extinction of mental faculties."

His opinion was graphically reinforced by the attitude of Whitworth who had placed his arm around the neck of the chief warder in the dock and oblivious to the circumstances was pointing directly at the judge with a hearty smile.

Channell: "He clearly would not know the difference between guilty and not guilty."

Lyford: "I do believe he would not, my lord."

Channell: "Does it appear to be of a permanent character."

Lyford: "I quite think so, my lord. It apparently rises from a disease which has been going on for some time. No doubt it arises from the softening of the brain which has been in existence for some considerable time previous to his coming into prison."

Channell then turned to the jury.

"It is an indictment of the most melancholy character for the murder of his wife and six children. It is a most melancholy and unfortunate case but the question simply here is whether he has really understanding sufficient to be able to plead. You will probably entertain little doubt he is unable to plead to the indictment, the effect of your finding is that he will be ordered to be confined during her Majesty's Pleasure in order to see what the result will be.

"He will not of course, as you may suppose, be allowed to go at large for doing so would be extremely dangerous. He will remain in safe custody and be properly treated for the disease under which he now labours.

"You will now say whether in your judgement he is fit to plead to this indictment."

Jurors without leaving their seats accepted he was not.

After the judge had passed sentence, the warder motioned Whitworth to leave the dock but such was the state of his mind that he could not understand. At length, he took him by the arm and gently led him away, whereupon Whitworth loudly exclaimed: "Gracious God, look down upon you all, miserable sinners."