Murder of Laurent Bonomo and Gabriel Ferez

On 29 June 2008, Laurent Bonomo and Gabriel Ferez, both French biochemistry students in their third year of a master's degree at Polytech Clermont-Ferrand, were killed in a flat rented by Bonomo in Sterling Gardens, New Cross, South East London. The two men were in London on a three-month DNA research exchange programme at Imperial College London. The victims were bound, gagged, and tortured over several hours before being stabbed 196 times (Bonomo) and 47 times (Ferez). A fire was deliberately started in the flat, and firefighters discovered the bodies. A post-mortem examination at Greenwich Mortuary found both men died from wounds to the head, neck, and chest before the fire took hold, and a petrol-like accelerant had been poured on their bodies.

Investigators established that the victims' bank cards and two Sony PSP handheld game consoles were missing and believed these items had been taken by the killers. The same flat had reportedly been burgled six days earlier, on 23 June 2008, with a laptop stolen. On 5 July 2008, the Metropolitan Police arrested a 21-year-old man, who was released the following afternoon without further action. On 6 July, police issued an e-fit of a suspect seen running from the scene, described as a white man aged 30 to 40, of slight or slim build, wearing a light-coloured baseball cap, a dark top marked "Junfan," blue jeans, and white trainers. Ferez's parents publicly appealed for information, and Detective Chief Inspector Mick Duthie renewed appeals for witnesses.

On 7 July 2008, Nigel Edward Farmer, 33, turned himself in at Lewisham Police Station with burn injuries and was treated in hospital before being interviewed in custody. That same day, roughly 600 students and residents in Clermont-Ferrance demonstrated in memory of the victims. On 8 July, a Greenwich Magistrates' Court judge granted police additional detention time, and the Southwark Coroner's Court adjourned the inquest for 28 days. On 10 July, Farmer was charged with both murders, arson, and attempting to pervert the course of justice, and was remanded in custody.

On 11 July 2008, police arrested Daniel "Dano" Sonnex, 23, in Peckham after his brother and a woman turned themselves in; Sonnex was charged on 12 July with murder and perverting the course of justice. His trial with Farmer began on 24 April 2009 at the Old Bailey. On 4 June 2009, both men were found guilty of murder. Sonnex was sentenced to a minimum of 40 years, and Farmer to a minimum of 35 years. It was disclosed that Sonnex should have been imprisoned at the time of the murders but had been released due to an administrative error; the chief officer of London Probation resigned amid the resulting investigation, and the UK Justice Secretary apologised to the victims' families, who indicated intent to pursue legal action against the authorities.