The use of anonymity in the New Year shooting trial set a legal precedent, making it a unique case.
Letisha Shakespeare and Charlene Ellis were killed by gunshots
For the first time in English law, one of the main witnesses was granted total anonymity, even though he was a known criminal with only the prosecution and judge knowing his true identity.
Known only by the false name of Mark Brown, he became a "pseunonymous" witness - a phrase coined at the start of the trial.
The jury, barristers and the judge all heard his real voice from the witness stand but a distorted voice was fed into the soundproof defendants' dock and into a separate annex court room where the public gallery and the press were stationed.
It was the testimony of Mr Brown which the defence teams argued would result in an unfair trial.
In his summing up to the jury, Nigel Rumfitt QC, defence for Marcus Ellis, pointed out: "As far as we are aware, no witness has ever been allowed to give evidence in the way Brown was in the entire history of our common law going back the best part of 1,000 years."
In an interview with BBC News Errol Robinson, part of the defence team for Mr Ellis and Mr Beckford, said giving anonymity to Mr Brown was "dangerous".
"It is one thing where a little old lady is allowed to give anonymous evidence where there is no point of contention about credibility, but when you are talking about someone (Mark Brown) who can be demonstrated to be part of gang activities, someone who has demonstrated to have lied repeatedly - it was quite wrong, dangerous and unfair to have allowed such an individual to give evidence anonymously.
"We (the defence) were not allowed to discuss anything that would lead to the identification of the main anonymous witness.
"It meant therefore that we could not investigate or make our own investigations as to the background credibility of that individual.
"If someone is accusing you of anything, let alone a matter of this gravity, you really ought to know who that person is so you can investigate the motives for that person giving evidence so that there is a fair trial."
The Crown Prosecution Service (CPS) disputes the trial was unfair.
David Blundell, chief Crown Prosecutor for the West Midlands, said it was the most complex case he had been involved with in more than 30 years.
He said: "Generally all the civilian witnesses were reluctant to become involved.
"The reason why the investigation lasted nearly a year before anyone was charged was because of the difficulties around the investigation.
"One of the things police had to address was how we could persuade witnesses who had seen or heard relevant evidence to come forward. Witnesses were not prepared to give evidence without protection.
'A tremendous challenge'
"The Crown Prosecution Service got together with leading counsel and police and agreed we would apply to the court to make witnesses anonymous - they wouldn't have to give their names to the court, they would have to give their evidence behind screens and when they gave their evidence, their voices would be electronically distorted so the defendants would not know who was giving evidence against them."
Mr Blundell said anonymity can be, and is, granted from time to time in court but admitted the trial was unique in that it was the first time a witness whose credibility was challenged was allowed anonymity.
He added: "The boundaries have been moved forward and I think that will be very helpful in the future for crime detection.
"The prosecution had to make massive inquiries into the background of all the witnesses and all the background had to be disclosed to the defence so it wasn't as if the defence didn't know about the people.
"It has been a tremendous challenge and it has not been easy but through this case, the whole justice system has been challenged and the courts have responded positively.
"I hope people will be encouraged to come forward and give evidence in future. It is now up to the community to play their part."