Vikram Dodd: The video was undoubtedly dramatic, and it could not have failed to have at least some effect on the jury

The appeal of Gary Dobson and any subsequent appeal by David Norris will centre on whether the trial judge was right to allow covert video to be played to the jury, showing them making vulgar racist comments and fantasising about inflicting violence on black people.

During the Old Bailey trial which led to Dobson and Norris's conviction for the murder of Stephen Lawrence, their barristers tried to stop the covert video being played to the jury as evidence that Dobson and Norris held racist views and had the capacity for violence.

The video was undoubtedly dramatic, and it could not have failed to have at least some effect on the jury. The question will be whether the jury was properly influenced.

Few are surprised by Dobson and Norris's challenge to their convictions; it would have been a bigger surprise if they had not.

The lodging of an appeal does not mean the convictions will be tested again in a higher court. The court will now decide if they will grant an appeal hearing.

Even if they do, there are several large hurdles the defence would have to overcome.

Mr Justice Treacy gave careful written directions to the jury as to how they should consider their verdicts. He clearly stated that the jurors must first be sure that the forensic evidence tieing Dobson and Norris to murder scene was reliable and not due to contamination. Only then, ordered the judge, could the jury consider the covert video.

Furthermore, the lord chief justice has already ruled that the scientific evidence against Dobson was so compelling that it merited the quashing of his 1996 acquittal for the Lawrence murder, which was necessary to allow him to stand trial again.

On top of that is the fact that Dobson had to admit telling lies to police in interview and that Norris's evidence in his own defence was disbelieved by the jury.

Before Dobson and Norris's lawyers attempt to surmount those hurdles, they will have to convince the court of appeal that Treacy, who is a high court judge, was wrong to admit the video.