Sarmad Al-Saidi was knifed 12 times in the chest and legs at his friend's home on Chatham Place, Deepdale, Preston, on December 23, with the blood loss causing a cardiac arrest and, in turn, brain, liver and kidney damage through the resulting lack of oxygen.
Despite the best efforts of the paramedics and doctors he did not regain consciousness and died four days later, jurors at Liverpool Crown Court were told.
Jamie Dixon, 18, of Clayton Avenue, Leyland, and two Preston boys aged 17 and 16, who cannot be named for legal reasons, are charged with murder.
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The 16-year-old has already pleaded guilty to murder, and Dixon has pleaded guilty to manslaughter, but Dixon and the 17-year-old remain on trial for murder at Liverpool Crown Court before His Honour Mr Justice Goss.
Jurors have been told of the defendants' varying accounts of what happened, but the prosecution allege all three had been planning the attack for days and were "determined to ensure that this was a violent end to longstanding acrimony between them."
The 17-year-old says that although he had initially been on friendly terms with Sarmad, there were a couple of occasions when they fell out about money and in particular £25 that was owing for some cannabis that was given to him by Sarmad.
He claims on December 23 he went to sort this out at the house, taking a baseball bat with him because he says he knew Sarmad had a machete.
Prosecuting, Nicholas Clarke QC said: "Sarmad was in the conservatory with his two friends.
"As he arrived he could see through into the conservatory and he and Sarmad laid down their respective weapons.
"He says they talked about the problems and also ongoing issues between (the 16-year-old) and Sarmad.
"He claims he was warning Sarmad that (the 16-year-old) was out to get him. He claims that he received a call from (the 16-year-old) while he was there and told him that Sarmad was not there to prevent (the 16-year-old) from causing any trouble.
However the court heard Jamie Dixon gives a different account, claiming he went round to the side of the house and into the conservatory with the 16-year-old as part of a plan to rob Sarmad of his cannabis stash.
He says it was the 16-year-old's idea, that he just went along to help, and that the plan was "just to scare" Sarmad.
When Sarmad tried to escape into the house Dixon says he stabbed him in the leg with a knife, which was then handed to the 16-year-old.
Jamie Dixon says he then changed his mind about the robbery and wanted to leave but the 16-year-old was repeatedly stabbing Sarmad, which he tried to stop.
Mr Clarke said: " These three defendants had been planning to attack Sarmad for several days. They were determined to ensure that this was a violent end to longstanding acrimony between them.
"There had been an earlier encounter the previous summer where knives were used and Jamie Dixon had received a cut hand. Separately, some money was owed.
"Sarmad was marked out for violent revenge. They just needed to identify where he hung out and how they were going to attack him."
The jury was told about text evidence which showed on December 21 the 16-year-old defendant sent a text to Jamie Dixon saying: “Got a drop on Sarmad Bro ring me later” and within seconds Jamie Dixon responded saying “Ride out any day for my man”.
On December 22 in a voice recording recovered from the 16-year-old’s SnapChat recorded someone saying: “Don’t give ‘em more second chances, ‘cause a second chance is like giving someone a gun again, you know what I mean. Like saying shoot me again you know what I mean”.
Prosecutors say further audio notes on Snapchat from December 23 show the trio tried to recruit others to assist them and as they refined the plan of attack, including the idea of a kidnap, one was recorded saying: “Someone gonna’ get stabbed up in a house bro it ain’t a joke”.
It is alleged Jamie Dixon and the 16-year-old had been keeping observations in the cul de sac for over 50 minutes and knew from contact with the 17-year-old that Sarmad was still in the conservatory and was unarmed.
The court heard at 5.35pm, the 16-year-old and and Dixon put on balaclavas and entered the conservatory, Dixon with a machete and the 16-year-old with a hunting style knife.
The 17-year-old was seen to move out of the way as they came in and attacked Sarmad Ali-Saidi, "striking and stabbing at him with the weapons as Sarmad curled up in a ball on the floor in an attempt to protect himself".
Mr Clarke said: " The attack lasted just a couple of minutes. Importantly there was no question of asking for any cannabis stash or of it being a robbery at all. This was a no questions asked all-out attack. The use of both a knife and a machete show it was designed to inflict immediate serious harm to Sarmad.
"They were not there just to hurt him a little bit."
Sarmad's friend's mother was in the kitchen when she heard noise and commotion in the conservatory, but the kitchen door through to the conservatory was locked and she couldn’t get through.
Her son managed to unlock the door, and she saw figures running from the conservatory and Sarmad injured on the floor.
She spoke to the emergency services and instructed her son what to do to help Sarmad whilst waiting for the paramedics to arrive.
The blood loss was so severe that medics performed a procedure called an emergency thoracotomy at the scene, before he was taken to the Royal Preston Hospital.
He never regained consciousness and was pronounced dead on December 27.
It is alleged Dixon and the boy "revelled in what they had done", with a video recorded on the teen's phone and Dixon allegedly saying he had just caught this kid and “done him” and that it was "hot to chat about" in a call from a friend at a young offender's institution.
The defence case is due to start today.
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