As thousands of police officers search across France for a convict who escaped prison in a commando-style helicopter raid Sunday, investigators are piecing together how the precisely coordinated, astonishingly brazen caper came together — probably through months of high-tech spy work and secret plans.

Rédoine Faïd, a 46-year-old gangster and career criminal, had been serving a 25-year sentence for armed robbery and murder at Sud Francilien Penitentiary Center. For obvious reasons, not a lot is publicly broadcast about the security measures in place at the prison, about 25 miles southeast of Paris in Reau.

According to an old brochure, the facility houses 500 male and female prisoners on an “exceptional” campus featuring meadows, embankments, water channels, and nearly 10,000 plants, shrubs and trees.

Amenities notwithstanding, the prison was supposed to be secure even for a man like Faïd, whose record of robberies, hostage takings and violence dates back to the 1990s, and who escaped once before in 2013.

So Sud Francilien’s exceptional landscape was covered in what the Associated Press called “anti-helicopter netting” — the entire grounds, except for one large and seldom-used courtyard.

This was the weak link in the prison’s design, around which Faïd’s accomplices on the outside began plotting.

“Someone spotted this possible way out, and it could have been done using drones,” Justice Minister Nicole Belloubet told reporters, according to the Guardian. She said several such machines had been spotted overflying the prison several months ago.

With an infiltration point into the prison identified, the conspirators set about acquiring the machinery and talent to exploit the security gap.

Faïd had at least three willing accomplices, according to French authorities. None of them knew how to fly a helicopter, apparently — so on Sunday morning, the men kidnapped a pilot as he waited for a flight lesson, according to the Guardian.

They forced the pilot at gunpoint to fly them to the prison in an Aerospatiale Alouette II, a light utility chopper. It was a warm morning, and the small, bright white helicopter might have looked almost cheerful as it flew over Sud Francilien’s thick foliage and touched down in the courtyard, shortly before noon.

Then two of the gunmen jumped out of the craft. They were now wearing masks, according to Reuters. They also wore hoods, “police” armbands and carried Kalashnikov rifles, according to the Guardian.

“It was an extremely well-prepared commando unit,” Belloubet told reporters. And it had all the tools, weapons and expertise it needed to carry out a clockwork-precise attack on the prison’s internal security.

Faïd was in the visiting room talking to his brother at that moment, the Guardian wrote. The gunmen in the courtyard allegedly set off gas canisters and smoke bombs as a distraction, and used an electric grinder to get through the visiting room door.

The two gunmen then escorted Faïd back to the helicopter, where the third was still guarding the pilot.

Faïd in November 2010. (IBO/SIPA/AP)

Faïd’s escape spurred a massive manhunt across greater Paris, which involves at least 2,900 French security forces and checkpoints along the Belgian border, according to the Guardian. The French National Police said Sunday it had mobilized its forces and urged people to notify authorities with any pertinent information.

Within hours of the escape, the helicopter was found abandoned and burned in a field in Gonesse, a suburb just northeast of Paris.

The kidnapped pilot had been released unharmed, the Associated Press wrote.

Faïd is believed to have made the next stage of escape in a ground vehicle, which was later found abandoned in Aulnay-sous-Bois, another Paris suburb, the BBC reported.

The convict’s brother was arrested and is being questioned, Reuters wrote. As of Tuesday morning, he was the only person linked to the operation known to be in police custody.

Sunday’s escape was not the first time that Faïd had pulled off a dramatic prison break. In 2013, he managed to escape from a prison in Lille, France, by taking four guards hostage and then detonating explosives hidden in a tissue box to blow out the prison gates, local news outlets reported. He was recaptured six weeks later at a hotel in suburban Paris — but not before he briefly claimed the title of France’s “public enemy number one,” the Independent reported.

As John Lichfield wrote for the Independent after the widely reported 2013 escape, Faïd was inspired by the crime bosses and schemes depicted in old Hollywood films:

As a young delinquent in a troubled suburb north of Paris, Faïd took his inspiration, and modus operandi, from American gangster movies. “Take away the [lessons taught by] cinema and you would have 50 per cent less crime,” he once told Michael Mann, the director of Heat (1995), his favourite film.

In a raid on a security truck in 1997, Faïd and his associates wore ice-hockey masks like the hero-villains of Heat. Three years ago, when he envisaged giving up crime for a career in the movies, he boasted: “I see everything in CinemaScope.” Faïd’s other hero is Jacques Mesrine, the most celebrated French criminal of modern times. Mesrine also turned his life into a kind of movie script, with interviews and letters to newspapers, before he died in a police ambush on the northern outskirts of Paris in 1979.

Faïd has a violent criminal record dating to at least the 1990s, when he organized the robberies of banks, shops and armored vehicles. He took families, couples and a police officer hostage, according to the Telegraph.

He spent years as an international fugitive before his capture and a decade in prison, then wrote an autobiography after his release on parole in 2009. In it, he claimed to have been inspired by the U.S. gangster film “Scarface,” the Telegraph wrote, but he claimed his life of crime was behind him.

The same year the book came out, the Telegraph wrote, Faïd was suspected of masterminding a botched armed robbery in which a police officer was killed in a shootout. He received an eight-year prison sentence in 2011 — interrupted by the 2013 breakout.

An April 2013 photo shows the international wanted notice for Rédoine Faïd on the Interpol website. (Interpol/AFP/Getty Images)

T.J. Ortenzi contributed to this report, which has been updated with new information.

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