After years of denial, the Polish son-in-law of billionaire Hélène Pastor has confessed to ordering a mafia-style hit on the 77-year-old property heiress.
Wojciech Janowski is on trial with nine others and made the shocking admission a day before the verdict is due.
The 2014 shooting of Pastor and her chauffeur in Nice shook the principality of Monaco, where she was a friend of the royal family.
His lawyer Éric Dupond-Moretti told the Aix-en-Provence court on Tuesday his client “is guilty of ordering Hélène Pastor’s murder”.
“These words which you wanted to hear from him come from my mouth. He tried to say these words, he wanted to say them but he couldn’t,” he said with Mr Janowski crying beside him.
At the time of the killing, Mr Janowski had the title of Poland’s honorary consul to Monaco. His lawyer said his actions were to protect his common-law partner Sylvia Pastor from her mother, who he alleged had made her life a misery.
He also claimed he had not ordered the two hit men to kill Pastor’s driver, but another defendant in the trial has contested this.
A verdict is expected on Wednesday, local media reported, and prosecutors are seeking a life sentence for Mr Janowski.
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 at 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 local time (17:00 GMT) 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 3.5m 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.
Mr Dauriac claims his employer ordered Pastor’s driver to be killed and her purse stolen to make the incident look like a robbery.
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 the 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.
Until his latest admission on Tuesday, Mr Janowski had been defiant under questioning, telling prosecutors to “show me the proof”.
He had claimed his confession in 2014 stemmed from difficulties in understanding French, and told a local newspaper earlier this year from prison that everything had been done to make him look guilty.