The investigation into the murder of Peter Falconio, in the Australian Outback, and the Madrid train bombings, drew on forensic expertise across the world.

Now some of those investigators are bringing their expertise to bear on the Ann Heron murder. Nigel Burton reports.

Peter Falconio was a British tourist who disappeared in the Australian outback while travelling with his girlfriend, Joanne Lees, in July 2001.

The 28-year old was travelling along Stuart Highway, near Barrow Creek, when he stopped the car to help a man. Shortly after getting out of the vehicle, Joanne Lees heard a gunshot. She never saw her boyfriend again.

The terrified young woman was grabbed by her assailant, who bound her wrists, put a sack over her head and forced her into his vehicle.

She escaped into the Outback and alerted police, but Mr Falconio's body has never been found.

Two years later, Bradley Murdoch, a drug dealer living in Adelaide was found to have a DNA link to the case when he was arrested for a rape. Miss Lees subsequently identified him as the man who abducted her.

Forensic evidence would play a crucial role in his conviction. His DNA matched blood on Joanne Lees's T-shirt, he left a smear of blood on the gearstick of the couple's car and DNA was found on the tape used to bind her wrists.

However, forensics were unable to find any bullets or evidence of any bullets being fired at the scene of the crime, either in the van or on the ground nearby.

An expert forensic anatomist said that Murdoch was almost certainly the person who was captured on video at the Alice Springs truck stop early on July 15, 2001, just hours after the murder of Peter Falconio.

Horrific as it was, the Falconio case was minor compared to the massive investigation that took place into the train bombings in Spain.

On the morning of March 11, 2004, a series of bombs exploded on the Madrid commuter train system, killing 191 people and injuring more than 2,000 others,

The bombings were the worst terror attack in Europe since the Lockerbie bombing in 1988.

They were directed by an al-Qaeda terror cell, although direct participation by al-Qaeda has never been firmly established.

Another bombing was attempted on a high-speed train track on April 2, but this time it proved unsuccessful. Shortly afterwards, police had a break when they identified an apartment south of Madrid that had been used as a base of operations for the men behind the attacks.

But when police raided the apartment, the four men trapped inside committed suicide rather than being taken alive.

The investigation then switched to how the bombers could have bought 200kg of explosives. Forensics later established that they had been bought from a retired miner who still had access to blasting equipment.

Twenty nine people, mostly Moroccans, were eventually charged in connection with the bombings.

Their trial began in February this year, with more than 100 expert witnesses and forensic investigators due to give evidence.