LONDON, England – It could be labelled a triumph for the British judicial system: Preventing three innocent men from going to prison for a crime they didn't commit.

That's certainly the way the jury saw it.

The only suspects ever charged in connection with London's 7/7 attacks have been found not guilty of conspiring with the bombers in 2005.

Waheed Ali, 25, Sadeer Saleem, 28, and Mohammed Shakil, 32, admitted being close friends of the bombers but through two trials they have denied ever knowing about the plot or helping them carry it out. The men were originally tried in 2008, but the first jury deadlocked and failed to reach a verdict.

For the victims' families, both trials have disclosed painful reminders of how and why the four suicide bombers were so intent on killing as many as possible on that day.  The three defendants always maintained they did not believe in suicide bombings.

But as Ali put in courtroom testimony: "If I agreed with [the bombings], I would have been there on 7/7 with the brothers, with a rucksack on my back...I would have killed hundreds," Ali told the jury before adding, "They didn't stop them, they wouldn't have stopped me. Not your MI5, not your MI6, not nobody."

Ali and Shakil were found guilty during this second trial of plotting to attend a terrorism training camp in Pakistan at the time of their 2007 arrest. They will be sentenced on Wednesday.

Still, Ali repeatedly accused the prosecution of being on a "witch-hunt" and of pursuing charges against him purely for political reasons.

While Scotland Yard's commanders would deny those accusations they will now face more scrutiny not just about this investigation, but their entire posture towards counter-terrorism investigations.

For years Scotland Yard has been trying to prove that the London bombers did not act alone. They gathered thousands of pieces of evidence that in the words of prosecutors, "fit together like a jigsaw to produce a compelling picture of guilt."

But they have failed to prove that in court.

Add to this failure, the release of 12 suspects last week after a high-profile investigation into a so-called ‘Easter-Plot.' Police here have yet to press a single charge in connection with an incident that the British government continues to describe as a "serious terrorist plot."

That investigation was brought forward after Britain's top counter-terrorism cop, Bob Quick, nearly blew the case by being photographed holding clearly legible briefing notes on the operation. Quick was forced to resign.

And then there is the airline plot now currently being re-tried in Britain. Seven men stand accused of plotting to blow up transatlantic airliners using liquid bombs. But again, the prosecution failed to win convictions last year after the jury deadlocked and authorities were forced to prosecute the case from scratch.

All of this has served to undermine the credibility of Britain's counter-terrorism strategy.

The government has spent billions on fighting and prosecuting terror but Britain remains a significant global frontline. With all the adversity and scepticism it is now receiving in prosecutions and investigations, security authorities are open to new scrutiny about whether they are up to the job or even irresponsibly exaggerating the terror threat.