A man convicted of murder after egging on a friend to stab a former policeman is mounting a Supreme Court challenge.
Five Supreme Court justices are due to analyse Ameen Jogee's appeal against his conviction at a hearing in London today.
Jogee and his friend, Mohammed Hirsi, who are both in their 20s, were given life sentences after being convicted of Paul Fyfe's murder at Nottingham Crown Court in March 2012.
Jurors heard that Hirsi stabbed Mr Fyfe at a house in Leicester in June 2011 while being egged on by Jogee.
A judge imposed a minimum 22-year term on Hirsi, who lived in Leicester, and a minimum 20-year term on Jogee, who was of no fixed address.
Jogee's minimum term was later cut to 18 years by the Court of Appeal.
Jogee has already lost fights over his conviction in the High Court and the Court of Appeal.
The Supreme Court hearing is due to end later this week.
Supreme Court justices are being asked to grapple with a legal issue relating to the fact that Jogee did not wield the knife - but urged Hirsi to do so.
Lawyers for Jogee will ask the justices to consider what prosecutors had to prove in order to establish that the killing was a "joint enterprise" rather than a lone act by Hirsi.
A summary of the central issue - published on the Supreme Court website - says: "(The) issue (is) whether the prosecution must prove that a secondary offender, who encouraged the primary offender to commit some harm, foresaw the primary offender's acquisition and use of a weapon for murder as 'probable' rather than 'possible' in order to establish joint enterprise."