Jury fails to reach verdict in July 7 bomb case

LONDON, England (CNN) -- A jury in London failed to reach a verdict against three men charged in connection with the July 7, 2005, bombings on three underground trains and a bus in which 52 people were killed and hundreds wounded.

The four bombers died in the blasts, but Waheed Ali, Sadeer Saleem and Mohammed Shakil were accused of helping the four by conducting reconnaissance and conspiring with them.

Following a three-month trial at Kingston Crown Court and two weeks of deliberations, a jury of eight women and four men could not decide on a verdict and were discharged on Friday.

All three defendants were charged with conspiracy to cause explosions.

Jurors began deliberating July 14. On Monday, the judge told jurors they did not have to reach a unanimous verdict, but needed a majority verdict of 10 out of 12 jurors.

At least 900 people were wounded in the blasts.

It was evidence found at the bomb sites that first led police to Ali, Saleem and Shakil. Investigators found the mobile phones of two of the suicide bombers, Mohammad Siddique Khan and Germaine Lindsay. Khan's phone had numbers for Saleem and Shakil, and Lindsay's phone had a number for Ali.

Police arrested the three in March 2007 after piecing together what they called a "complicated jigsaw with thousands of pieces." They were charged in April 2007.

The discovery of the mobile phones allowed investigators to start tracing the call records and determining how closely the men were connected.

"With call records these days, you can not only obtain the data of the calling party, which is the suspect's phone, but also the data of the called party, even down to which mast the called party was using," said Greg Smith, a mobile forensics expert.

Police said they analyzed more than 4,700 phone numbers and 90,000 calls. They discovered the three men had made a trip to London in December 2004 -- seven months before the fatal bombings -- which prosecutors claimed was a reconnaissance trip to scout potential targets.

Prosecutors said that on December 16, 2004, the men traveled from the northern English city of Leeds to London, along with Hasib Hussain, one of the July 7 bombers. When they got to the capital, they met with Lindsay.

Over the next two days, prosecutors said, the men visited tourist sites including the London Eye ferris wheel, the London Aquarium and the Natural History Museum, as well as underground train locations. Some of the spots, prosecutors said, were near where the July 7 bombs were eventually detonated.

Police called it "the first feasibility study" for the London bombings.

The three men, who always denied the charges, acknowledged making the trip but said it was just an innocent outing to visit Ali's sister in London.

Saleem told the court that he had had "no idea whatsoever" about the plot.

Traces of DNA linked all three alleged accomplices in some way to the bombers, police said. Investigators found Ali's fingerprints on evidence found at the bomb-making sites.

Khan, Lindsay, Hussain and a fourth bomber, Shehzad Tanweer, set off a series of bombs the morning of July 7, 2005. They exploded on underground trains near Liverpool Street, Russell Square and Edgware Road and on a double-decker bus at Tavistock Square.

Police have said they don't believe the investigation should end with the three men.

"I firmly believe that there are other people who have knowledge of what lay behind the attacks in July 2005 -- knowledge that they have not shared with us," said Peter Clark, head of the Metropolitan Police Counter Terrorism Command, when the men were charged in May 2007. "In fact, I don't only believe it. I know it for a fact."