NEW YORK, NY.- Nils M. was no rookie art thief. But prosecutors say he left behind DNA evidence on a broken picture frame at one museum and on a heavy-duty strap at another that helped Dutch investigators identify him as the man who stole paintings by van Gogh and Frans Hals in two daring heists.

A match in their database led them to the 59-year-old defendant who had previously served a five-year prison sentence for stealing a 17th-century gilded silver monstrance, or church vessel, from a museum in Gouda in 2012.

During that theft, Nils M. — who is being identified without his full surname because of Dutch privacy laws — used explosives to blow open the museum door.

In the more recent thefts, prosecutors are seeking a prison sentence of eight years for what they described as “exceptional crimes” that were committed with an as yet unidentified partner. The paintings — the van Gogh had an insured value of 2.5 million euros (about $2.9 million), and the Hals was valued at between 10 and 15 million euros (between $11.7 million and $17.6 million) — have not been recovered.

A three-judge panel is expected to rule on the case Friday.

“Breaking into a museum and taking paintings by artists who are world famous, pieces that belong to our cultural heritage, that are irreplaceable,” was “totally unacceptable,” the prosecutor in the case, Gabriëlle Hoppenbrouwers, said in court this month, according to a copy of the indictment.

In the court hearing, in Lelystad, the defendant denied the charges. “He said that he didn’t steal those paintings and he had nothing to do with it,” said his lawyer, Renske van Zanden.

But public prosecutors for the Central Netherlands region said that the DNA evidence from the picture frame and the strap, which was likely used in the getaway, points to him.

The van Gogh painting, “The Parsonage Garden at Nuenen in Spring,” from 1884, was part of a temporary exhibition at the Singer Laren Museum, on loan from the Groninger Museum in Groningen.

Security camera footage of the robbery last year showed a man using a sledgehammer to smash two glass doors to break into the museum. He left with the painting under his arm.

Prosecutors said the painting’s frame was left behind in pieces in the parking lot. Some of those pieces bore traces of the suspect’s DNA, they said.

The Hals painting, “Two Laughing Boys with a Mug of Beer,” from the 17th century, was stolen five months later, in August 2020, from a tiny museum, Museum Hofje van Mevrouw van Aerden, in Leerdam. That robbery drew special notice because it was the third time that the painting had been stolen from the same small museum. (It was previously stolen in 2011 and 1988, but recovered both times.)




The back door had been broken open and police found an orange tension strap tied to a flagpole in the garden outside the museum that prosecutors believe was likely used to lower the Hals or the thief down a nearby 10-foot wall to a waiting scooter. A security camera showed two people driving away on the scooter. The passenger was carrying something square that looked like a small painting.

Also discovered two weeks before the robbery in Leerdam was an extendible ladder, submerged in a stretch of water near the base of the museum’s garden wall that prosecutors suspect could have been hidden there by the burglars to scale the wall. A passerby, however, noticed the ladder and moved it, possibly thwarting part of their plan, investigators said.

Prosecutors emphasized the strength of the DNA evidence at each of the scenes. But they said there were other compelling reasons to suggest the two thefts were carried out by the same man. Both thefts occurred sometime shortly after 3 a.m., involved heavy force to break into the museums, and involved an accomplice who helped the thief get away on a scooter, they said. Investigators have not identified an accomplice.

The museum in Leerdam is part of an almshouse for unmarried women that also showcases the collection of its 18th-century founder. It is largely run by volunteers who maintain the Hofje and its garden. Prosecutors said a trampled zucchini plant had helped investigators work out where the thief had climbed over the wall into the garden.

The defendant, Nils M., was arrested in April at his home in Baarn, a small town close to Laren. A firearm and ammunition were found in a search of his home, as were more than 10,000 ecstasy pills, prosecutors said.

Answering the charges in court earlier this month, Nils M., who works as a mechanic, said that he sometimes used the kind of strap found in Leerdam when he carried out repairs, which could explain the presence of his DNA on the strap. But he did not know how the strap got to Leerdam, his lawyer, van Zanden, said.

“He said that he often uses straps, for instance when he picks up car parts,” she elaborated in an email. “He also said that the straps were sometimes left behind.”

Van Zanden maintained that the DNA evidence from Laren was inconclusive, partly because there were matches to other people on the picture frame. She said that her client is taller than the man shown on the Laren footage, and said that the way the thief handled the hammer on the video suggested he was left-handed, while her client is right-handed.

The theft of the artworks by the two major Dutch artists within the period of a few months spawned numerous theories about why they had been stolen. In court, Hoppenbrouwers said prosecutors believed that the defendant had sold or given the paintings away, and they were now in the criminal underworld.

In the indictment, she suggested some reasons famous artworks remain popular among thieves even though they cannot be easily sold or displayed publicly. Such masterworks can have currency in the underworld, investigators believe, because they can be used to demand ransoms from the insurance companies that insure them and, in some cases, can be used in negotiations to obtain reduced prison sentences.

The works might also be used as collateral in drug deals, she said.

Arthur Brand, a private art detective who has followed both cases, said that he believes there is demand in the Dutch underworld for artworks. People accused of drug crimes think that a stolen artwork could potentially be surrendered to the authorities in exchange for a lesser sentence, he said.

This article originally appeared in The New York Times.