On 16th December 1910, a gang that included Dubof, attempted to break into the rear of Henry Harris's jeweller's shop in Houndsditch, from 11 Exchange Buildings in the cul-de-sac behind. The Daily Telegraph reported: "Some two or three weeks ago this particular house in Exchange Buildings was rented and there went to live there two men and a woman. They were little known by neighbours, and kept very quiet, as if, indeed, to escape observation. They are said to have been foreigners in appearance, and the whole neighbourhood of Houndsditch containing a great number of aliens, and removal being not infrequent, the arrival of this new household created no comment. The police, however, evidently had some cause to suspect their intentions. The neighbourhood is always well patrolled. Shortly before 11.30 last night there were sounds either at the back of these newcomers' premises or at Mr Harris's shop that attracted the attention of the police."

A neighbouring shopkeeper, Max Weil, heard their hammering, informed the City of London Police, and nine unarmed officers arrived at the house. Sergeant Robert Bentley knocked on the door of 11 Exchange Buildings. The door was open by Gardstein and Bentley asked him: "Have you been working or knocking about inside?" Bentley did not answer him and withdrew inside the room. Bentley gently pushed open the door, and was followed by Sergeant Bryant. Constable Arthur Strongman was waiting outside. "The door was opened by some person whom I did not see. Police Sergeant Bentley appeared to have a conversation with the person, and the door was then partly closed, shortly afterwards Bentley pushed the door open and entered."

According to Donald Rumbelow, the author of The Siege of Sidney Street (1973): "Bentley stepped further into the room. As he did so the back door was flung open and a man, mistakenly identified as Gardstein, walked rapidly into the room. He was holding a pistol which he fired as he advanced with the barrel pointing towards the unarmed Bentley. As he opened fire so did the man on the stairs. The shot fired from the stairs went through the rim of Bentley's helmet, across his face and out through the shutter behind him... His first shot hit Bentley in the shoulder and the second went through his neck almost severing his spinal cord. Bentley staggered back against the half-open door and collapsed backwards over the doorstep so that he was lying half in and half out of the house."

Sergeant Bryant later recalled: "Immediately I saw a man coming from the back door of the room between Bentley and the table. On 6 January I went to the City of London Mortuary and there saw a dead body and I recognised the man. I noticed he had a pistol in his hand, and at once commenced to fire towards Bentley's right shoulder. He was just in the room. The shots were fired very rapidly. I distinctly heard 3 or 4. I at once put up my hands and I felt my left hand fall and I fell out on to the footway. Immediately the man commenced to fire Bentley staggered back against the door post of the opening into the room. The appearance of the pistol struck me as being a long one. I think I should know a similar one again if I saw it. Only one barrel, and it seemed to me to be a black one. I next remember getting up and staggered along by the wall for a few yards until I recovered myself. I was going away from Cutler Street. I must have been dazed as I have a very faint recollection of what happened then."

Constable Ernest Woodhams ran to help Bentley and Bryant. He was immediately shot by one of the gunman. The Mauser bullet shattered his thigh bone and he fell unconscious to the ground. Two men with guns came from inside the house. Strongman later recalled: "A man aged about 30, height 5 ft 6 or 7, pale thin face, dark curly hair and dark moustache, dress dark jacket suit, no hat, who pointed the revolver in the direction of Sergeant Tucker and myself, firing rapidly. Strongman was shot in the arm, but Sergeant Charles Tucker was shot twice, once in the hip and once in the heart. He died almost instantly.

As George Gardstein left the house he was tackled by Constable Walter Choat who grabbed him by the wrist and fought him for possession of his gun. Gardstein pulled the trigger repeatedly and the bullets entered his left leg. Choat, who was a big, muscular man, 6 feet 4 inches tall, managed to hold onto Gardstein. Other members of the gang rushed to his Gardstein's assistance and turned their guns on Choat and he was shot five more times. One of these bullets hit Gardstein in the back. The men pulled Choat from Gardstein and carried him from the scene of the crime.

Yourka Dubof, Yakov Peters, Peter Piaktow and Fritz Svaars, half dragged and half carried Gardstein along Cutler Street. Isaac Levy, a tobacconist, nearly collided with them. Peters and Dubof lifted their guns and pointed them at Levy's face and so he let them pass. For the next half-hour they were able to drag the badly wounded man through the East End back streets to 59 Grove Street. Max Smoller and Nina Vassilleva, went to a doctor who they thought might help. He refused and threatened to tell the police.

They eventually persuaded Dr. John Scanlon, to treat Gardstein. He discovered that Gardstein had a bullet lodged in the front of the chest. Scanlon asked Gardstein what had happened. He claimed that he had been shot by accident by a friend. However, he refused to be taken to hospital and so Scanlon, after giving him some medicine to deaden the pain and receiving his fee of ten shillings, he left, promising to return later. Despite being nursed by Sara Trassjonsky, Gardstein died later that night.

The following day Dr. Scanlon told the police about treating Gardstein for gun-shot wounds. Detective Inspector Frederick Wensley and Detective Sergeant Benjamin Leeson arrived to find Trassjonsky burning documents. Soon afterwards, a Daily Chronicle journalist arrived: "The room itself is about ten feet by nine, and about seven feet high. A gaudy paper decorates the walls and two or three cheap theatrical prints are pinned up. A narrow iron bedstead painted green, with a peculiarly shaped head and foot faces the door. On the bedstead was a torn and dirty woollen mattress, a quantity of blood-stained clothing, a blood-stained pillow and several towels also saturated with blood. Under the window stood a string sewing machine, and a rickety table, covered with a piece of mole cloth, occupied the centre of the room. On it stood a cup and plate, a broken glass, a knife and fork, and a couple of bottles and a medicine bottle. Strangely contrasting with the dirt and squalor, a painted wooden sword lay on the table, and another, to which was attached a belt of silver paper, lay on a broken desk supported on a stool. On the mantelpiece and on a cheap whatnot stood tawdry ornaments. In an open cupboard beside the fireplace were a few more pieces of crockery, a tin or two, and a small piece of bread. A mean and torn blind and a strip of curtain protected the window, and a roll of surgeon's lint on the desk. The floor was bare and dirty, and, like the fireplace, littered with burnt matches and cigarette ends - altogether a dismal and wretched place to which the wounded desperado had been carried to die." Another journalist described the dead man "as handsome as Adonis - a very beautiful corpse."

The police offered a £500 reward for the capture of the men responsible for the deaths of Charles Tucker, Robert Bentley and Walter Choat. One man who came forward was Nicholas Tomacoff, who had been a regular visitor to 59 Grove Street. He told them that he knew that identities of three members of the gang. This included Yakov Peters. On 22nd December, 1910, Tomacoff took the police to 48 Turner Street, where Peters was living. When he was arrested Peters answered: "It is nothing to do with me. I can't help what my cousin Fritz (Svaars) has done."

Tomacoff also provided information on Yourka Dubof. He was described as "twenty-one, 5 feet 8 inches in height of pale complexion, with dark-brown hair". When he was arrested he commented: "You make mistake. I will go with you." He admitted that he had been at 59 Grove Street on the afternoon of 16th December 1910. He said he had gone to see Peter, who he knew was a painter, in an attempt to find work, as he had just been sacked from his previous job. At the police station Dubof and Peters were identified by Isaac Levy, as two of the men carrying George Gardstein in Cutler Street.

On 23rd January, 1911, A. H. Bodkin, opened the case for the Crown against Yourka Dubof, Yakov Peters, and Nina Vassilleva. He made a major mistake in arguing that it was George Gardstein who had shot Robert Bentley and Charles Tucker: "Gardstein was the man who came in flinging open that back door and shot Bentley at his right front; there were also other shots from the man on the stairs.... Several shots were fired at Bentley by the man Gardstein from the back, he advanced to the front door of the house, of that there is no doubt, for we have the hand, according to the evidence of Strongman, protruding through the door of No. 11, so as to sweep the place, firing at Woodhams, Bryant and Martin."

Bodkin based his analysis on the discover of the Dreyse gun in Gardstein's room: "Now Gardstein - under his pillow at 59 Grove Street was found exhibit No. 2, which was a Dreyse pistol. A pistol with a magazine, which on examination had been recently fired. It is difficult to say - for any expert to say - when it had been recently fired. It was a pistol rifled in four grooves, and Mr Goodwin, a gentleman who has kindly examined this pistol... has fired some shots from that pistol into sawdust. The cartridges which can be fired from that pistol are quite common cartridges which are standardised and are used for various automatic pistols, but the peculiarity of this Dreyse pistol is that it has four grooves. It appears that six bullets - two from Tucker's body, two from Bentley's body and two from Choat's body - were fired from the Dreyse pistol as they all have four groove marks upon them.... It is clear that Gardstein was the man who fired, and under his pillow a Dreyse pistol was found, and it seems quite proper to assume that he it was who used the Dreyse pistol. The only one to hit Bentley was Gardstein, and Bentley's bullets were from a Dreyse pistol."

What the prosecuting counsel had difficulty explaining was the lack of Dreyse ammunition in Gardstein's house. As Donald Rumbelow, the author of The Siege of Sidney Street (1973) has pointed out: "Now it has been wrongly assumed from Mr Bodkin's statement that the pistol was under the pillow for Gardstein to defend himself and to resist arrest. In support of this theory it has been alleged that a cap containing a quantity of ammunition was placed by the bed within easy reach of his hand. Certainly there was a cap with ammunition by the bed but none of it could be fired from the Dreyse... If, in fact, Gardstein had owned the Dreyse, it is reasonable to suppose that some ammunition for this weapon would have been found in his lodgings, which were described as an arsenal as well as a bomb factory. None was found." Rumbelow goes on to argue that the only ammunition "consisted of ... 308 .30 Mauser cartridges, some of D.W.M. (German) manufacture, and the other with plain heads; also 26 Hirtenberger 7.9 mm Mauser rifle cartridges". Rumbelow adds that "it is inconceivable, surely, that a man would have over 300 rounds of ammunition for a Mauser pistol which he didn't possess, and none for the Dreyse he is supposed to have used!"

Rumbelow suggested that Yakov Peters had planted his Dreyse gun in the room when along with Yourka Dubof, Peter Piaktow and Fritz Svaars, he had taken Gardstein to 59 Grove Street. Peters realised that Gardstein was dying and that the police would eventually find his body. If they also found the gun that had done most of the killing, they would assume that Gardstein was the man responsible for the deaths of the three policemen.

The case was adjourned when another gang members were arrested in February, 1911. The trial of the Houndsditch murders opened at the Old Bailey on 1st May. Yourka Dubof and Yakov Peters were charged with murder. Peters, Dubof, Karl Hoffman, Max Smoller and John Rosen were charged with attempting to rob Henry Harris's jeweller's shop. Sara Trassjonsky and Nina Vassilleva, were charged with harbouring a felon guilty of murder.

The opening speech of A. H. Bodkin lasted two and a quarter hours. Justice William Grantham was unimpressed with the evidence presented and directed the jury to say that the two men, against whom there was no evidence of shooting, were not guilty of murder. Grantham added that he believed that the policeman were killed by George Gardstein, Fritz Svaars and William Sokolow. "There were three men firing shots and I think they are dead."

The prosecution's principal witness that linked Peters and Dubof to Gardstein was Isaac Levy, who saw the men drag him along Cutler Street. Levy came under a fierce attack from defence counsel. After his testimony, Justice Grantham said that if there was no other evidence of identification he could not allow any jury to find a verdict of guilty on Levy's uncorroborated statement. After Grantham's summing-up made it clear that none of the men should be convicted of breaking and entering, the jury found them all not guilty and they were set free.