David Potter was stabbed to death in his Tooting High Street flat
Christopher McMahon has been found guilty of manslaughter
A homeless man has been found guilty of the manslaughter of David Potter in Tooting High Street last year. 48-year-old
Christopher McMahon, of no fixed abode, was found guilty at the Old Bailey this Thursday (21st February) and has been sentenced to ten years in prison in relation to the death of 50-year-old David Potter at his flat.
Detective Chief Inspector Mark Cranwell, of the Homicide and Major Crime Command led the investigation. He said, “The weight of evidence against Christopher McMahon was compelling and left the jury in no doubt that he was responsible for the brutal killing of David Potter.
“As this investigation developed, it became clear that McMahon was an unpredictable character who used threatening behaviour to intimidate people into getting his way.
“He will now spend a considerable amount of time in prison and I hope McMahon’s conviction brings some sort of closure to David’s family following what has undoubtedly been a horrific time for them.”
The court heard how David lived in a studio flat above a shop on Tooting High Street and often socialised with drinkers in the local area.
On 26th March 2018 at around 2.45pm, one of his associates called police with concerns for David’s welfare as he had not seen him for several days. He had been round to his flat but David was not answering and he also noticed mail building up outside the address.
Officers forced entry to the flat and found David’s body on the floor in a pool of blood - an initial assessment established he had been dead for some time. A post-mortem examination concluded he had suffered slash wounds to the neck, one of which had severed an artery.
On examining the flat, officers found a number of distinctive bloody footprints on the floor. They also found correspondence addressed to a ‘Christopher McMahon’.
From speaking to witnesses, including the owner of the shop David lived above, it became clear that David had last been seen on the evening of 20 March 2018. CCTV from inside the shop showed David speaking to staff before leaving at 10.45pm and heading up to his flat. At around 11pm a man, later identified as McMahon, was also seen on CCTV in the shop before heading towards the flat.
The same CCTV cameras showed McMahon leaving the flat at around 2.40am on 21st March.
Enquiries established that McMahon was already in police custody as he had been arrested on for other offences including an incident of criminal damage at a woman’s address where McMahon had kicked in her door to gain entry. Her address was near to where the murder took place. The criminal damage took place three or four days before David Potter was murdered and the woman told police she had seen McMahon with a knife in the weeks leading up to the fatal stabbing. The woman let McMahon into her home after he banged on her door. She was concerned that he would break the door so let him in.
Police recovered unwashed clothes covered in blood from a washing machine at this address which were covered with blood and the woman revealed that McMahon had been drunk, saying repeatedly “I’ve done him in” and “I slit his throat”.
Forensic analysis of the clothes confirmed that the blood on them belonged to David.
Police also established that another man had been living with the victim in his flat in Tooting. He confirmed that he was asleep in the flat on the night of the stabbing and when he woke at about 2am he saw both David and McMahon in the flat.
Around this time, David was telling McMahon about a previous conviction he had for a sexual offence. The man felt uncomfortable and left the flat.
February 22, 2019