Stevenage’s Mark Altabas was stabbed to death after trying to steal drugs from an armed dealer, a court heard today.

On the opening day of a five-week trial at the Central Criminal Court at London’s Old Bailey, a jury heard how 18-year-old Destao Pedro – who denies murdering MrtAltabas – had allegedly returned from stocking up on class A drugs in London to a house he regularly visited in Long Leaves, Stevenage, to supply drugs.

Crown prosecutor Stuart Trimmer said Mr Pedro – of Forest Road, Walthamstow – was sitting on the sofa at the address on April 21 this year when 48-year-old Mark Altabas came in with two other men, a Mr Cuthbert and Mr Mooney.

He said the trio had planned the robbery in advance and were in collusion with the second defendant, Robert Crook, who often bought drugs from Mr Pedro, lived at the house and allegedly tipped off the men who turned up armed with knives.

The court heard Mr Altabas went into the house and asked Mr Pedro if he could have the drugs ‘on tick’ – ie he would pay for them later – but when Mr Pedro refused the two of them got into a scuffle.

Mr Pedro – who was allegedly armed with a large carving knife – sustained a deep wound to his left wrist and arm at some point, before the trio tried to escape from the house.

Mr Altabas was the last to get out and, as he left, he was heard to cry: “Ah my back”.

He only got 50 yards from the house before collapsing.

Police and paramedics were called at around 4am and tried to save Mr Altabas, but he was later pronounced dead by doctors at Stevenage’s Lister Hospital.

An autopsy later revealed he had suffered six stab wounds in the back, one of which had punctured his aorta.

Officers found Mr Pedro, Mr Crook and third defendant Katie Holmes at the house, with prosecutor Trimmer alleging the former had numerous blood stains on his jogging bottoms.

The court heard some of the blood DNA samples have been found to match that of Mr Altabas.

When interviewed by police, Mr Pedro denied he was at the scene and denied he had a knife.

He later said he had been at a party and then was upstairs staying at the house before he went down to answer the door to four men.

He claimed one of them stabbed him with a knife before he ran upstairs and escaped through a bedroom window.

Mr Mooney, who will appear as a witness, claims he saw Mr Pedro lunge at Mr Altabas with a knife and shouted: “I’m going to kill you”.

Mr Trimmer showed the jury text messages which he said were evidence of contact between Mr Altabas and Mr Crook on the day leading up to the robbery, proving they were in collusion.

Other messages, he said, showed contact between Mr Altabas and Mr Pedro.

The court heard after the murder that Mr Crook or Ms Holmes sent a message from a shared phone to Mr Altabas, who they thought was still alive, saying: “What have you done, I let you into my home, why inside my home?”

Ms Holmes, who also lived at the property, cleaned the knife used in the stabbing and cleaned blood from the kitchen floor – Mr Trimmer told the jury. The 43-year-old denies one count of attempting to pervert the course of justice.

Ms Holmes and Mr Crook, 57, previously admitted conspiracy to supply class A drugs, something Mr Pedro denies.

Ms Holmes has also admitted allowing her home to be used for the supply of class A drugs, while Mr Crook denies conspiring to rob Mr Pedro.

The trial is expected to continue until at least December 22.