The Copenhagen Hypnosis Murders

“Like Waking from a Bad Dream”: March 1951, Frederiksberg

Late March in Copenhagen is a strange season, the city caught between winter’s last grip and the slow thaw of spring. On March 29, 1951, as the low sun stretched across Frederiksberg Allé, most of the city’s worries felt ordinary—ration cards, errands, children hurrying home from school before supper. But as the hands on the Haand-i-Haand bank’s brass clock inched past 3:30, the mundane would shatter—leaving behind two lifeless bodies, a bag of stolen cash, and a question still echoing decades later: can a man be compelled to murder, not by threat or desire, but by another’s whispered command?

Old Acquaintances and the Power of Persuasion

To understand why the bank’s tiled lobby became a crime scene, you have to start a few years earlier—behind the iron gates of Denmark’s Horsens State Prison.

Palle Hardrup was the sort of man who never quite found his footing. During the dark years of the German occupation, he’d stumbled into petty crime and ended up behind bars, quiet but impressionable. There, he met Bjørn Schouw Nielsen—a sharply intelligent inmate with a taste for the esoteric. If Hardrup was a man searching for guidance, Nielsen was all too willing to provide it.

Nielsen was fascinated by the mind’s hidden recesses. Fellow inmates said he could fix you with a look that lingered longer than comfortable. He read about yoga, mysticism, and, most of all, hypnosis. He spoke in a voice tuned to draw secrets out of the air. Some believed Nielsen was a little unhinged; others saw him as dangerous.

After they both left prison, the two kept in touch. But in the months leading up to March 1951, something changed. Friends and neighbors noticed it first: Hardrup, always quiet, seemed hollowed out—jumpy, distracted, almost mechanical in his routines. He began visiting Nielsen regularly. Some said their conversations were disturbingly intense; others recalled Hardrup, wide-eyed, muttering about destiny and obedience.

March 29: Blood in the Bank

No one at the Haand-i-Haand branch expected trouble—banks in Copenhagen rarely saw anything worse than a bounced check. That afternoon, with the air still and heavy, Palle Hardrup stepped inside and walked straight past the oak counters.

He drew a pistol. In four quick shots, everything changed.

Bank manager Einar H. Sørensen, 40, and cashier Merete Bagger, 27, collapsed on the checkered floor. The air, thick with cordite and panic, sent staff scrambling for cover and bystanders running outside.

Hardrup moved methodically. He scooped banknotes—70,000 Danish kroner, a small fortune then—into a battered bag. Less than two minutes after entering, he turned and left, blending into the thin stream of pedestrians outside.

He didn’t get far. Police, already nearby after a witness raised the alarm, spotted him just down the block—still clutching the money. There was no firefight, no chase. Hardrup simply stood, looking lost, as officers closed in.

“I Was Following Orders”: The Interrogation and the Puzzle

Back at headquarters, detectives expected the usual: fear, bravado, maybe a confession. But Hardrup sat in his cell, unmoving, unable—or unwilling—to explain himself. He seemed confused, as though he didn’t recognize his own actions. When pressed, he muttered about having followed “orders,” actions he didn't recall planning. He was blank, then agitated, then oddly calm.

Seasoned investigators sensed something off. The crime was coldly efficient by a man known for timidity and indecision. Rumors swirled about drug use or a breakdown. But as days became weeks, small clues pointed toward something stranger.

Detectives traced Hardrup’s final weeks. He’d spent long hours with Nielsen, and neighbors described eerie, late-night lectures about mind control and free will. Hardrup’s family felt he’d been “not himself” for months. Theories gathered like dust. Then a detective—perhaps half in jest—wondered aloud: could Hardrup have been hypnotized into killing?

Peering Into Shadows: The Investigation Broadens

Hypnosis, in 1950s Denmark, sat uneasily between stage trick and science. Hardly the sort of defense that wins sympathy in court. But as investigators dug deeper, they found strange patterns.

Nielsen, when questioned, was smooth—too smooth. He denied everything, but acquaintances recalled him bragging he could “use” someone to commit the perfect crime. He’d dabbled in spiritual philosophy and read voraciously about controlling the subconscious. Police began tailing him, interviewing his friends, and seeking out anyone who might have witnessed the pair rehearsing “suggestion” rituals.

Psychiatrists were called in. Hardrup, under examination, exhibited what now might be called dissociation, sometimes “forgetting” who he was, often terrified and weeping. One psychiatrist concluded he was highly suggestible. Another wasn’t sure but warned of the danger of “psychic domination” in the wrong hands.

It was outlandish. But evidence—letters, witnesses, audio tapes—began to suggest Nielsen’s hold over Hardrup was more than mere friendship.

The Trial: Justice in Uncharted Territory

By 1954, the case had become a national obsession. Was it a murder, a manipulation, or both? Newspapers ran speculation side-by-side with updates from the courtroom. People gossiped in trams and cafés, wondering: If a man could be hypnotized into murder, what did that mean for any of us?

In court, Hardrup appeared gaunt, often staring at the floor. Nielsen sat with an air of patience, trading thin smiles with his lawyer. The prosecution called experts on hypnosis, criminal psychology, and even philosophy. Testimony revealed Hardrup had demonstrated deep hypnosis—they even managed to induce him into a trance, on record.

The prosecution painted Nielsen as a “criminal Svengali," arguing he’d slowly conditioned Hardrup to obedience, planting post-hypnotic commands, using spiritual jargon to break his will. Defense lawyers argued the whole thing was nonsense—a fairy tale, an excuse for a killer.

But records, letters, and Hardrup’s bizarre behavior swayed the judge. Eventually, the court delivered a verdict unprecedented in Danish history: Nielsen was guilty not as a direct participant, but as an instigator—having compelled Hardrup to kill through hypnotic influence.

Hardrup was sentenced to indefinite detention at the “king’s pleasure.” Nielsen too was sentenced, less for pulling a trigger than for orchestrating someone else to do it.

Ripples: Aftershocks in Law, Science, and Society

The city mourned for Sørensen and Bagger. At the Haand-i-Haand branch, business resumed shakily, but nothing felt safe for a long while. For the victims’ families, the loss was beyond repair.

For the law, and for Denmark as a whole, the case left scars—and questions. Could culpability be assigned to one man for crimes committed by another’s hand? How much sway does one mind have over another? Could a skilled manipulator co-opt a weak-willed follower, and where was the line between suggestion and coercion?

In the months after the trial, amateur hypnotists faced sharp scrutiny. Some shows and demonstrations were curtailed. Lawmakers debated, but ultimately, no specific laws were changed. Police, however, learned to pay closer attention to the psychological backgrounds of violent offenders.

Years Later: What Did We Learn?

Time moved on, and so did the people involved. Hardrup was later diagnosed with schizophrenia and spent the rest of his days in and out of mental institutions, dying in 2012. Nielsen served many years in prison and died in 1974, his reputation as Denmark’s “criminal hypnotist” cemented in both legend and legal textbooks.

The Copenhagen Hypnosis Murders became a fixture in European criminology and forensic psychology. The central premise—that a man could be turned, almost puppet-like, into a killer—remained disputed. Some experts argue the court overestimated hypnosis’s power, that Hardrup was feeble-minded and manipulated, but not truly controlled. Others saw the episode as proof that the human mind, under the right stress—or in the wrong hands—might do almost anything.

In Denmark, the case is still cited in legal and psychiatric circles for its thorny questions about responsibility, agency, and the shades of gray between victim and perpetrator.

For most, though, the lesson lingers in quieter ways—in a nervous glance at a stranger’s eyes, or in a shiver at the thought that, in some ways, not even your own mind may be entirely your own.

Memory on Frederiksberg Allé

Today, those who walk Frederiksberg Allé rarely notice the old Haand-i-Haand branch. Its doors have changed; its secrets are buried deeper. But if you look close on a quiet afternoon, the shadows seem longer—reminders that beneath the orderly rhythms of ordinary life, there are stories of strange power and deeper darkness.

And that sometimes, the question is not simply who committed a crime, but how far the invisible hands behind it truly reached.