It's the most important criminal case you've never heard of. A tale of political conspiracy and assassination, set against the background of the violent 1980s cocaine trade.
In life, Colombia's 1989 presidential candidate, Luis Carlos Galan, was South America's version of JFK; charismatic, visionary, admired and fearless.
More than 20 years after his murder the comparisons to JFK continue.
Galan was gunned down in public. TV cameras recorded the moments leading to and including his death. And yet, like JFK, the truth behind his killing has never emerged. Nobody, it seems, knows who killed Luis Carlos Galan.
One senior Colombian official once told me Galan's fate could be summed up in the title of a Gabriel Garcia Marquez novel. "His life reads like the chronicle of a death foretold", he said.
In the absence of an undisputed, legally proven case, a 'generally accepted' version of events around Galan's murder has developed. It goes something like this:
In lawless, 1980s Colombia, Liberal politician Galan was the only person willing to stand up to cocaine drug lords, such as the notorious Pablo Escobar.
Galan's election pledge was to get tough on the drug trade by extraditing the likes of Escobar to the US for trial and punishment. Escobar feared this more than anything and was determined to prevent it, so organised for Galan to be dealt with. He wanted to make an example of him.
Egged on by one of Galan's political rivals for the presidential candidacy, a man called Alberto Santofimio, Escobar made his move.
On the evening of 18 August, 1989 Galan was assassinated as he walked on stage to address thousands of supporters at a political rally close to Bogota. That night Colombia lost its saviour and Escobar became public enemy number one.
Eventually he was hunted down by US and Colombian forces and brought to justice. He was shot and killed in a chase across the rooftops of a Medellin property. His bloated dead body was photographed and ridiculed for the world to see.
Mark Bowden's Killing Pablo remains the most accepted account of the hunt for fugitive Escobar.
Thankfully, many of today's, young, ambitious and educated Colombians have moved on from the violence and tiresome stereotypes of moustachioed drug dealers. Colombia has developed a new reputation as a safe, cutting-edge tourist destination - it's also developing its international trade links. Many of the ghosts of 1980s drug violence are gradually being put to rest.
There is no better example of this process than Nicholas Entel's award winning documentary, Sins Of My Father, where the sons of Escobar and Galan are united in condemning those dark days.
But before Colombia can fully move on, the unanswered question must be addressed: Who killed Galan? The 'generally accepted' version of events does not hold water. For closer analysis, rewind to 1988, a year before Galan's killing.
It is an undisputed fact that during that year, British mercenaries were secretly hired by Colombian army generals to deal with the other big threat to Colombia's national security, FARC.
According to David Tomkins (who was one of the mercenaries hired) in his book Dirty Combat, the fighters were recruited by a man called Jorge Salcedo.
Salcedo, the son of one of the generals, was tasked with organising an attack on the leaders of FARC. Private foreign mercenaries were used because the generals couldn't convince the political leaders to attack - diplomacy was considered a stronger weapon. Rather than disobey their elected leaders, the generals went behind their backs.
Tomkins says his mission was privately funded by associates of Escobar in the Medellin cocaine cartel. He says this was because Escobar wanted to exterminate FARC, who were a common enemy as they were a challenge to his expanding drug empire. But also army money could not be used to fund what was essentially an illegal, unauthorised mission.
Tomkins writes at length of his experiences in the Colombian jungle and about how his original mission to attack FARC lost its way. He was instead asked to show untrained Colombians how to build bombs, use weapons and fight like soldiers.
A second account of this time in 1988 was provided by another of the mercenaries, Peter McAleese , in his book No Mean Soldier.
Significantly, these British fighters were not the only mercenaries hired during this period.
Israeli mercenaries led by a man called Yair Klein also took part in the military training and arming of Medellin cartel forces.
While it's all to easy to get entangled and lost in the complexities of what occurred during his time, it is important to focus in on one point. Medellin cartel employees were trained to fight, bomb and shoot by people who'd been brought to Colombia at the request of the country's own army generals.
Following this to its logical conclusion, while Escobar undoubtedly issued the final order to kill Galan, it's possible argue he may never have done it without the trained fighters the army had inadvertently handed him.
Is the truth of who killed Galan far too uncomfortable for Colombia's top rank to confront?
The story of the man at the centre of all this, Jorge Salcedo, is truly fascinating.
A recently published book by Bill Rempel, the former investigations editor of the LA Times, chronicles Salcedo's murky, yet remarkable life.
A year after working with Escobar, Salcedo swapped sides and went to work for his arched rivals, the Cali cartel. Salcedo hired Tomkins and McAleese a second time for a mission to kill Escobar. It failed and both British mercenaries almost lost their lives. Full and colourful accounts of their exploits in Colombia are provided in their previously mentioned books.
Eventually, Salcedo turned on his bosses in the Cali cartel and exposed them to US federal officers. In 1995 he managed to bring the multi-million dollar criminal enterprise to its knees. Salcedo has a lot of questions to answer. There is, however, one huge problem. He cannot be contacted. He now lives a secret life, with a new identity on the US witness protection programme. It was one of his rewards for bringing the Cali cartel to justice.
As Rempel (who has rare, but occasional contact with Salcedo) reveals in excellent detail in At The Devil's Table, he performed a heroic, yet largely unsung, role in the fight against cartel corruption and the cocaine trade.
But all of the good threatens to fades into insignificance until he is able to answer what happened with his well intentioned, yet fatally flawed role in arming Escobar with a trained fighting force.
Salcedo may well be innocent of any crime, but for anyone looking at who killed Luis Carlos Galan, Salcedo surely holds a lot of clues.
Follow Stephen Hull on Twitter: www.twitter.com/hullstephen