A man who set two dogs on a 16-year-old gang rival before stabbing him to death was found guilty of his murder at the Old Bailey today after his dog’s DNA was linked to the crime scene.

Oluwaseyi Ogunyemi died after he was stabbed six times in Larkhall Park, Stockwell, on April 27 last year, while his friend Hirui Hiyabu, 17, was stabbed nine times but survived.

Both victims suffered dog bites after the attack involving up to 15 youths, some masked and carrying weapons, from rival groups.

Crisdian Johnson, 22, Wyvil Road, Clapham, denied murder and attempted murder but was found guilty by a unanimous verdict.

His brother, Shane Johnson, 20, was found not guilty of the charges. A third defendant, 18-year-old Darcy Menezes, of Clapham, was cleared earlier in the trial.

Brian Altman QC, prosecuting, earlier told the court: “What was so unusual if not unique about this case is that in the initial stages of the attack both these dogs were deployed as weapons.

“At the time of the attack both dogs were unleashed, and chased and then brought down and savaged their victims, giving their human masters an advantage, enabling them then to access their victims in order to stab them with knives.”

The court heard the groups had been patrolling the Lansdowne Green estate in Stockwell earlier that evening and the victim was in a group of six from the nearby Stockwell Gardens estate.

Mr Altman said: “Witnesses spoke of both of these groups as being on a mission or as having a common purpose.

“The attack was described by one shocked onlooker as vicious and as mirroring the behaviour of a pack of wild animals . . . the twist to the story of this case is that the victims were attacked not only by the attackers but also by dogs.”

The dogs used in the attack, a large brown pit bull and mastiff cross named Tyson and a smaller brown Staffordshire bull terrier and pit bull cross called Mia, were recovered by police.

Tyson, who received two stab wounds during the incident and was taken to a Blue Cross hospital for treatment, was owned by Crisdian Johnson.

Police followed a trail of blood leading from the murder scene to nearby Sheldon Court. Forensic analysis showed it to be from a dog.

The blood was matched to Tyson by Gen Probe Dog DNA specialists.

A Metropolitan Police spokesman said: “This groundbreaking forensic work matched the blood from the trail to Tyson's DNA to a match of one in one billion.”

Speaking after the verdict, Detective Inspector Mick Norman, of the Met’s homicide and serious crime command, said: “This horrific attack was committed on a very slight teenage boy who stood no chance of defending himself.

“The fact that Crisdian Johnson also ordered dogs to take part in the attack illustrates his sickening attitude to violence. The advances in dog DNA and forensic work now means that anyone who owns a dog and uses it to attack people can be identified and prosecuted.”

Crisdian Johnson will be sentenced at the Old Bailey tomorrow.

How events unfolded after the first police call.

At 8.26pm on police were called to Larkhall Park after hearing a number of males were stabbed.

Witnesses described seeing a group of males with two dogs surround Oluwaseyi and Mr Hiyabu and attacking them like “a pack of wild animals”.

Oluwaseyi received six stab wounds and died at the scene at 9.15pm. His friend received nine wounds but survived.

A postmortem examination revealed Oluwaseyi, who suffered from Crohns Disease and was very slightly built, had six stab wounds to the abdomen, three of which were superficial.

The fatal stab wound entered via the right armpit and nicked the aorta causing catastrophic bleeding. He also had dog bites on his right calf, thigh and shoulder.

Just 13 minutes after the attack two Lambeth police officers saw Chrisdian Johnson “bare chested and covered in blood” walking along Wandsworth Road and arrested him on suspicion of murder.

A Metropolitan Police spokesman said: “They made all efforts to preserve any forensic material by treating him as a crime scene. This good practice enabled detectives to identify DNA found on his body and clothing as matching Christopher as well as Tyson."

A few hours after the attack Shane Johnson presented himself at Kings College Hospital with a stab wound and was subsequently arrested.