An inquiry into the torture and shooting of a teenager is to continue despite the conviction of seven people in connection with the murder.
Mohammed Omar Akbar fled the country after being charged
Daniel Higgins, 18, of West Drayton, Middlesex, was killed in a house in Burnham, near Slough, in November 2003.
Mohammed Omar Akbar, 29, of Slough, was found guilty of murder on Thursday.
Det Supt Mark Warwick said: "Although seven people have now been convicted in connection with Daniel's murder, this case has still not concluded."
Akbar's girlfriend, Rupinder Gill, 27, of Hounslow, was found guilty of assisting an offender, while Zahir Hussain, 27, of Slough, admitted assisting an offender.
They will be sentenced on 27 January at Reading Crown Court.
Akbar, of Eastbridge Road, and Hussain, of Griffin Close, both fled the country after being charged in connection with the murder and were arrested in Barcelona in March, having been on the run for almost 16 months.
Gill, of Roseville Avenue, was arrested in May 2004 and was later charged in September 2004.
Det Supt Warwick said: "The verdicts should send out a clear message to anyone who thinks that they can be involved in such a horrendous crime and then flee the country.
"Daniel's killing was particularly brutal and extremely violent. His death was a reprisal attack for the murder of Mohammed Mahmood in February that same year.
"Two families have lost loved ones and it is those families who continue to suffer.
In November 2004, Majad Khan, 29, of Wexham Road, Slough, was found guilty of murdering Mr Higgins and was jailed for life, to serve a minimum of 20 years.
Two 27-year-old men were also found guilty of assisting an offender, while a third man, also aged 27, pleaded guilty to the same offence; they were sentenced to seven, five and four years respectively.