Four years after billionaire Hélène Pastor and her chauffeur were fatally shot outside a hospital in the south of France, her son-in-law and nine others have gone on trial over the murders.
The shooting in Nice shook the principality of Monaco, where the 77-year-old property heiress was a friend of the royal family.
Her son-in-law, Wojciech Janowski, is alleged to have ordered the attack.
He initially admitted the crime before retracting his confession.
At the time of the killing, Mr Janowski had the title of Poland's honorary consul to Monaco. Now 69, he told a local newspaper earlier this year from prison that everything had been done to make him look guilty. His lawyers also believe he had no legal help at key moments of the inquiry.
"I will answer every question," he said as the trial opened on Monday.
Who was Hélène Pastor?
Her family was known as second in importance in Monaco only to the royal Grimaldi family. She was a descendant of Italian stonemason Jean-Baptiste Pastor, who arrived in Monaco in 1880.
By the 1930s he and his son Gildo had begun amassing a business empire, building apartment buildings and collecting rent. In 1966 Prince Rainier gave Gildo permission to build high-rise properties along the seafront. Instead of selling the properties, the family rented them out.
Hélène Pastor was the last of Gildo's three children and had a son and daughter through two marriages. The family's fortune was spread across several companies and has been variously estimated as worth between €12bn (£11bn; $14bn) and more than €20bn.
By the time of her death, the Pastor family was said to control 15% of Monaco's housing stock.
Among her favourite pastimes was driving around Monaco in a London taxi, according to Paris Match magazine.
How was she attacked?
It was shortly after 19:00 on 6 May 2014, as Hélène Pastor left L'Archet hospital in Nice that she and her chauffeur, Mohamed Darouich, were ambushed.
She had been visiting her son Gildo Pallanca-Pastor, who had suffered a stroke, when a gunman opened fire with a sawn-off shotgun.
Darouich died of his injuries four days later but Pastor only succumbed to her wounds on 21 May. In the days before her death she was able to give investigators a description of her attackers and had intended to provide further evidence.
"I'm afraid, I want to see you again because I have more to tell," she was quoted as saying.
Police traced some 3.5 million phone calls and within weeks had made several arrests. They concluded that the plot had originated with Mr Janowski, who then enlisted his fitness coach, Pascal Dauriac, who in turn used his brother-in-law, Abdelkader Belkhatir, to find potential contract killers.
Two suspects from Marseille alleged to have carried out the killing were tracked down through security cameras, mobile phones and DNA found on a bottle of shower gel left behind in a hotel room. Samine Aïd Ahmed, 28, denies firing the gun, while Al Haïr Hamadi denies acting as his accomplice.
The alleged contract was worth €140,000, police said.
Why was she killed?
The investigating magistrate alleged that Mr Janowski's businesses were on the verge of collapse and when his common-law partner, Sylvia, was diagnosed with cancer in 2012 he realised he was facing financial ruin.
Hélène Pastor provided her son and daughter with a monthly stipend of €500,000, but this would have dried up if her daughter had died.
Mr Janowski's fitness coach was reported as saying: "Janowski tricked me... He said his mother-in-law was a monster."
Sylvia Pastor was initially questioned by police before being ruled out of the inquiry. She had been with Mr Janowski for 28 years and the couple had a daughter. She survived cancer and attended the start of her ex-partner's trial.
Prosecutors said they had traced significant financial transactions in Mr Janowski's accounts in the months before the murders.
The murder was initially linked to organised crime, before prosecutors began to suspect Hélène Pastor's son-in-law.
The trial in Aix-en-Provence is expected to last five weeks.