America imprisons a higher proportion of its citizens than anywhere else in the world, and Louisiana more than anywhere else in America.
It is estimated that 14 out of every 1,000 adults in the state is in prison.
This is the story of one of them, Robert Jones, who was jailed in the 1990s for killing a young British tourist in New Orleans.
It was a crime another man had already been convicted of, but he was prosecuted anyway.
The judge who sentenced the young father to life in prison now says his skin colour sealed his fate.
But even today, more than 23 years after he was arrested, Robert Jones is still not a free man.
British holidaymakers Julie Stott and her boyfriend Peter Ellis were on a trip to the US that was meant to be one they remembered for the rest of their lives.
It was a celebration of the couple's engagement, though they had decided not to announce the news until they returned to the UK.
On Tuesday 14 April 1992, having already visited Los Angeles and the Grand Canyon, the couple planned a night out in New Orleans. Julie chose a restaurant and later they went to see a Latin jazz band at the Cafe Brasil.
At about 11.30pm the couple were strolling back to their hotel through the city's historic French Quarter, laughing and fooling around with a balloon they had found on the street.
But suddenly, as they passed an old French convent, a man leaped out from the shadows, and pointed a gun at them.
He shouted at them to lie down, but the couple froze in panic staring at the gun. The next moment the man started shooting.
He fired two shots at Peter. One grazed the front of his shirt as he dived behind a parked car.
Then the gunman turned to Julie, who was still standing startled in the middle of the road. She began to turn to run but as she did two shots rang out.
She slumped to the ground.
The attacker turned, jumped into a car and sped off the wrong way down the one-way street.
Peter rushed to his fiancee's side, trying to revive her. There was no response.
He saw blood gushing from her arm and tried to stem the flow with his shirt. As he cradled her, he shouted for someone to call for an ambulance.
But the second bullet had hit her in the head, just behind the ear and she was dying of her wounds.
“When I got here, only Julie's clothes were left in the road. She had been taken away by the emergency medics,” says James Stewart, the murder detective called to investigate the killing.
He had no trouble showing me the exact spot where the attack took place more than 23 years ago.
“This crime scene is just burned on my brain. I remember it like it was yesterday.
Now an FBI agent based in Florida, Stewart says it was quickly apparent that Julie Stott's death was the result of a botched robbery.
The entire confrontation, he estimates, took less than 30 seconds.
While the details Peter Ellis gave were crucial, his description of the gunman was sketchy, so focused had he been on the gun.
Stewart did have leads - the bullets used by the gunman and witness descriptions of the attacker's car. But he also knew the pressure would be on to find the murderer quickly.
“At the time there were crime sprees in other American cities, like Miami, where tourists were targeted,” he says.
What Stewart had not bargained for was the hunger for the story in the British media, which got involved in a way that dramatically altered the course of the case - and the life of Robert Jones.
Stewart quickly learned some other important facts about the night of the murder.
Just minutes before the shooting of Julie Stott, and just a short distance away in New Orleans's French Quarter, another couple had been robbed at gunpoint.
And two hours after Julie was killed, another street robbery took place. Again the attacker was armed.
Crucially, in both cases, descriptions of the gun and a burgundy car with a white roof used by the attacker matched those given by witnesses after the killing of Julie Stott, and by the victims of a sadistic robbery and rape a week earlier.
It was clear that Julie Stott's killer had embarked on a violent one-man crime spree and had already carried out at least four attacks in the city.
Meanwhile, the UK media had begun crying out for this man to be brought to justice. Within days the Sun newspaper had offered a $10,000 reward.
That news spread quickly in New Orleans and suddenly calls to the police flooded in.
“Any time you throw around a lot of money like that, you're going to get all kinds of people calling in and all kinds of leads,” says Stewart.
Most of the tips were discarded, but then one came in that investigators thought they should explore further.
“The caller identified some guys. He said they had all been in a bar talking about the murder and giving details that made him think they had been involved,” says Stewart, who was by this stage getting desperate for a breakthrough.
One of those named by the caller was Robert Jones, a 19-year-old from a run-down neighbourhood who had already been in some scrapes with the law.
He had been suspected of selling drugs, and though he had never been convicted of any crime, police had his picture on file.
Soon after the tip came in, a woman who had been robbed, kidnapped and raped in a horrific, prolonged ordeal a week before the murder of Julie Stott, was in the police station for a follow-up interview.
The investigator interviewing her said the police had news of a potential suspect and showed her a series of photographs.
Looking at the first picture, the rape victim said the man was too young. The second she did not recognise at all. The third she put to one side, before looking through the others.
Ultimately, she went back to the third picture. That, she said, was the man who had attacked her.
The third photograph was of Robert Jones.
It was about 4am when police officers surrounded Jones's home.
“We were in bed asleep when we heard a lot of noise outside, and banging on the doors. All around we hear people shouting, 'Open up!'” says Kendra Harrison, then Jones's 17-year-old girlfriend.
She says the police made everyone - Jones and her, and their two young children, plus Jones's mother and his five younger siblings - lie flat on the floor.
Only then did they shout out who they were looking for.
Robert Jones was quickly in handcuffs and being hauled out of the house.
“He kept on asking them what he was being arrested for. We didn't understand what was going on. I was so lost and confused. We all were,” says Harrison.
“After they took Robert away there was chaos, tears. Everybody was crying all over the place.”
Later, Jones was shown on TV bulletins being taken to Orleans Parish Jail, bare-chested and with his hands cuffed behind his back, accused of the murder of Julie Stott. News crews interviewed tourists, who talked of their relief that a killer had been caught.
In the UK too, Robert Jones' arrest was being widely reported.
“The Sun traps Julie's Killer” ran The Sun's front-page headline.
The mayor of New Orleans was quoted congratulating and thanking the newspaper for offering the $10,000 reward that appeared to have led to the arrest (though there is in fact no evidence to suggest a reward was ever paid).
Inside the newspaper, above a picture of Robert Jones, was the headline, Beast of the Jungle.
He was a “junkie murderer”, the story said, going on to describe the squalid conditions in the Jones family house, and to accuse him of a string of crimes - rape, kidnapping and robbery, as well as the callous shooting of Julie Stott.
But Detective James Stewart was uncomfortable.
“It was hard not to publicise that arrest, the media were all over the case, but I thought the headlines were overblown because we knew there was a lot more work to do.”
“The only things we had from the murder scene were a car and a bullet casing, and we hadn't yet tied Robert back to either,” he says.
His misgivings proved well-founded.
On 20 April 1992, six days after Julie Stott was killed - and the very day British newspapers ran triumphant headlines about the killer being caught - another young couple walking through New Orleans was suddenly confronted by a gunman.
He ordered them to lie on the ground. They complied.
With jewellery that the couple then handed over, the attacker got away.
He drove off in a distinctive burgundy car with a white roof.
Thanks to what they had seen on the news, or read in newspapers, many in New Orleans believed that the violent attacker who had terrorised their city and killed a British tourist had now been caught.
But detectives, who had by this stage formed a special taskforce, knew otherwise.
They continued to look for the real gunman, and could not have hoped for better than what happened next.
It was reported that a car fitting the description given in all five crimes in the spree was parked outside a home in a poor area of the city - a housing development known as the Desire Projects.
When detectives went to investigate, they found what appeared to be the burgundy car with a white roof that witnesses had described.
More than that, a man identifying himself as the owner approached them, asking why they were sniffing around his car.
A sharp-eyed detective immediately noticed that both the ring and the wristwatch the man was wearing matched descriptions of items stolen during the crime spree.
On closer inspection, it was found that he was also wearing a gold chain stolen in another of the robberies - and a medallion and chain stolen during the rape.
The man, 30-year-old Lester Jones (no relation to Robert), was arrested.
In his car, four more rings stolen during the crime spree and a pair of round wire-rimmed glasses described by the rape victim were discovered.
And at his home there were clothes that matched those worn by the rapist, other items stolen during the robberies and one other crucial bit of evidence, in a jacket hanging in Lester Jones's bedroom wardrobe.
“In Lester's apartment we found a weapon and bullets,” says James Stewart.
“We quickly had them tested and the ballistics guy over in our lab was able to tie the gun to the bullet removed from Julie Stott's body.”
In the days that followed, some of the victims of the crimes - including the robberies immediately before and after the murder of Julie Stott - identified Lester Jones as their attacker.
“We had everything we could want,” says Stewart.
“I've always worked under the assumption it was one perpetrator, and we found him and he was going to jail. And once Lester Jones got convicted then I thought that the case was over with, it was done with,” says Stewart.
But incredibly, two years after his arrest, Robert Jones had still not been released.
And in March 1996, now 23 years old, he too went on to be convicted of some of Lester Jones’s crimes - the killing of Julie Stott and some robberies – and in his case the rape too.
No-one mentioned at the trial that Lester Jones had already been jailed for some of these offences.
Prosecutors described him as a dangerous associate of Robert Jones - a man convicted of violent crimes - insisting the two were friends.
That was despite the fact that detectives - including James Stewart - had told the prosecutor's office that they were not.
Even though the original tip implicating Robert Jones related to Julie Stott's murder, the trial focused almost solely on the charge of rape, and the identification made by the rape victim.
Prosecutors claimed that Robert had borrowed Lester's car and gun, carried out that attack, then given back Lester his car, weapon and all of the items he had stolen.
