PARIS — He is an accomplished, acrobatic burglar, one referred to here as “Spiderman.” But all Vjeran Tomic needed to break into this city’s Museum of Modern Art in the spring of 2010 and pull off a near-perfect heist were a few tools, a couple of plungers, pliers and a lucky star.
Before dawn that day, he had loaded his Renault with five masterpieces from Picasso, Braque, Matisse, Léger and Modigliani, worth over 104 million euros, or about $112 million. All he left behind were empty frames, leaning against the museum’s walls.
“It’s one of my easiest and biggest heists,” Mr. Tomic told reporters on Friday outside the courtroom where he and two men accused as accomplices were on trial for the thefts.
Mr. Tomic has been likened in news articles here to Arsène Lupin, a fictional thief of the early 1900s who terrorized well-heeled Parisians. He has made a living robbing luxurious apartments of their masterpieces, sometimes using an arbalest, ropes, snap hooks and a harness to scale facades and gain entry. In 2000 he stole works by Renoir and Braque from two Parisian apartments, which earned him one of his 14 convictions to date.
Born in Paris, Mr. Tomic, 49, grew up partly in Bosnia and Herzegovina, then part of Yugoslavia, where he learned the art of theft, he told reporters. By the age of 11, he was back in Paris and scaling walls near Père Lachaise Cemetery, leapfrogging his way from one tomb to another across the graveyard. He later perfected his climbing skills in the French Army.
The heist here at the Museum of Modern Art, though, barely taxed his skills, he said.
The starting point, according to prosecutors, was when an antiques dealer who had previously bought stolen goods from Mr. Tomic commissioned him to steal a painting by Léger.
Mr. Tomic said at trial that he concentrated his efforts on one of the museum’s bay windows. During several scouting visits, he discreetly sprayed the window’s mounts with acid so they could be easily dismantled later. Then, around 3 a.m. on May 20, 2010, he disassembled the window, removed the glass, cut the padlock and the chain of the metal grid behind it and entered the museum.
The alarm systems remained silent.
The seasoned thief soon grabbed Léger’s “Still Life With Candlestick.” As he set out to leave, Mr. Tomic told the three judges, he realized that he had more time because the alarms had not sounded.
Fabrice Hergott, 55, the director of the museum since 2006, told reporters during a break in the trial, “The system was not well set up.”
Soon, Mr. Tomic told the court, he had also picked out Modigliani’s “Woman With a Fan,” Picasso’s “Dove With Green Peas,” Braque’s “Olive Tree Near l’Estaque” and Matisse’s “Pastorale.”
“I liked the Matisse — it had a very nice color,” he told reporters.
After the two-day trial, which ended on Friday, the prosecutor requested that Mr. Tomic, who was charged with stealing cultural property, be sentenced to 10 years in prison and a €300,000 fine.
The heist amounted to stealing “five marvels, five masterpieces from humankind,” the prosecutor said. A verdict is expected at the end of the month.
Jean-Michel Corvez, 62, the antiques dealer said to have commissioned the heist, and Yonathan Birn, a 40-year old clockmaker, are both accused of receiving stolen goods and also face possible prison terms and fines. All three were charged with taking part in a criminal conspiracy to commit the thefts.
The defendants have all acknowledged that they had a role in the case and have pleaded guilty to lesser offenses, but they are fighting the more severe charge that they engaged in a criminal conspiracy before the break-in.
Mr. Tomic, an athletic-looking man with little hair, an eye for detail and an apparent interest in entertaining an audience, at times drew laughter from the courtroom as he gave a meticulous account of a heist that he characterized as dizzyingly easy.
His depiction of the lapsed security at the Museum of Modern Art, which is visited by 800,000 people every year and is home to over 10,000 works of art, has raised concerns.
Investigators, who initially suspected that Mr. Tomic had an accomplice inside the museum, found that none of the anti-intrusion systems were fully operating that day. Signals from sensor detectors never made it to the security guards. Grills inside the museum were left unlocked.
The same day as the heist, according to prosecutors, the paintings were discreetly passed on to Mr. Corvez, the antiques dealer.
Mr. Tomic was questioned about a year later, a few months after the police received an anonymous tip that he had bragged about the robbery at a party. He soon confessed to the crime and gave the police an account of Mr. Corvez’s role.
Investigators are puzzled about what happened to the paintings once they were passed on. They have not been recovered, and at the heart of the trial was the nagging question of whether they were hidden somewhere safe, sold or, worst, destroyed.
At some point in the trial, Mr. Corvez mentioned a Saudi buyer without providing additional details.
Selling the paintings would have been extremely difficult, said James Ratcliffe, the director of recoveries and general counsel at the Art Loss Register, an international database of missing and stolen works of art.
“These pictures are ones which could be identified by any art dealer or auction house or collector almost instantaneously,” Mr. Ratcliffe said in a phone interview.
Mr. Birn, the third defendant, told the judges he had panicked and discarded the paintings, which he had been asked to store, meaning that they could be lost for all time.
But not everyone believes his account.
William Bourdon, a lawyer who represented the City of Paris, which owns the museum, told reporters there was an “immense probability” that the three men had managed to set up a “smoke screen” to deceive the authorities, with the “hope and the ambition to one day retrieve their share of the loot.”