The man jailed for the gangland slaying of Raymond (Yankee) Rawlins yesterday launched an appeal against his conviction, saying gang evidence against him was unfair.David Jahwell Cox argued through his lawyer that a police sergeant should never have been allowed to give his opinion to the jury about his gang links.Prosecutors say Cox was one of two gunmen who shot Mr Rawlins 16 times as he entered a nightclub in his Court Street neighbourhood early on August 9, 2010.He was convicted of murder and using a gun to commit the crime by the unanimous verdicts of a jury in June, 2011.According to prosecutors, Mr Rawlins, 47, was murdered by the 42 gang to exact retribution against the Parkside gang for an attack earlier that night on a 42 member.Cox was named during the trial by police witness Sgt Alexander Rollin as a member of 42.He was hanging out at the Mid Atlantic Boat Club on the night in question when his friend and fellow gang member Julian Washington was shot and injured. Mr Rawlins, a father of ten, was killed less than an hour later.Prosecutors cited the ongoing gang warfare between Parkside and 42 as the motive for the slaying.Cox denied during his trial that he was a member of the 42 gang and denied having a grudge against Rawlins. He protested that he had nothing to do with the murder.Yesterday, defence lawyer Larry Mussenden objected to Sgt Rollin being called as a gang expert.“We say that he was not a gang expert,” explained Mr Mussenden, arguing that the officer did not meet the necessary legal criteria to be declared as such. For that reason, he said, he should not have been able to share his opinion about gang issues in Bermuda with the jury.Mr Mussenden said he has looked, without success, for information about witnesses being allowed to fulfill a “gang expert” function in UK court cases.“Labelling somebody as an expert has an effect on the jury,” he said. “There’s no evidence to prove the defendant was in any ongoing feud with the deceased.”The serious tone of the appeal lightened briefly when one of the three-strong panel of judges, Sir Robin Auld, inquired what the 42 gang sign looks like and endeavoured to demonstrate an incorrect symbol with his hands.Mr Mussenden obliged by demonstrating the correct version.The defence lawyer revealed that he has a list of up to ten separate grounds of appeal that he hopes to advance on Cox’s behalf. He said he will focus on allegations that Mr Rawlins was a police informant, and that there may have been other people with a motive to kill him.He explained that the defence lawyer who originally represented Cox, John Perry QC, only became aware of Mr Rawlins’ alleged informant status after Cox had been convicted by the jury, but it is an issue he wishes the Court of Appeal to consider.Other grounds of appeal include the manner in which the trial judge, Carlisle Greaves, summed up the case for the jury and the way identification evidence was presented.The Crown is contesting the appeal, and prosecutor Cindy Clarke is set to reply to Mr Mussenden’s points today.