Midsummer's Eve should have brought celebration to the Stockholm suburb of Nacka, but in June 2001, a teenager's brutal murder shattered the peace. Jennifer Andersson, a talented karateka with Olympic dreams, was found strangled outside Ektorp School. At first glance, it looked like a tragic misadventure. But the truth lay much deeper — in the hands of her respected karate trainer, 46-year-old Manolis Karagiannis.

Known to her family and friends as a driven, soft-spoken young woman, Jennifer had a bright future and a new boyfriend. But beneath the surface of her martial arts success lay an insidious power imbalance. Her coach, a man nearly three decades older, had been nursing a dangerous infatuation.

In this haunting true-crime narrative, we explore the events leading up to Jennifer’s final hours — from the stark white walls of Ekvallen sports hall to the lonely flowerbed where her life ended. We also follow the aftermath: a suicide attempt, courtroom revelations, and the scars left on a community that trusted the wrong man.

The Girl in the Gi

It was the eve of midsummer — that golden, lilac-tinged twilight that stretches across Stockholm like an eternal sigh. In Nacka, a leafy eastern suburb just beyond the city’s centre, the neighbourhood was winding down for the long weekend. Gardens were blooming, children were out late on bikes, and the scent of elderflower and freshly mown grass drifted lazily through the air.

Inside Ekvallen sports hall in Gustavsberg, the fluorescent lights cast a clinical pall over the echoing gymnasium. The only sound was the soft slap of bare feet on polished floorboards and the occasional bark of instruction in Greek-tinged Swedish. Jennifer Andersson — tall, graceful, and razor-focused — adjusted her gi and tightened the belt around her waist. Seventeen years old, with long straight hair and a quiet determination, she was already something of a legend in her youth karate league. She dreamed of the Olympics.

Across from her, watching with an intensity that made some parents quietly uneasy, stood Manolis Karagiannis — her trainer, mentor, and the man she had once trusted above all others. At 46, Manolis was a veteran of the sport, a Greek national who had relocated to Sweden in the 1970s and built a quiet life for himself in the outskirts of Stockholm. His knowledge was revered. His presence, respected. And yet, there was something else too — something unspoken.

That night, Jennifer had seemed distant. Distracted. Between drills, she confided to her best friend in the locker room that she was thinking of leaving the training group. "It's just... he watches me like I belong to him," she’d whispered, keeping her voice low. “I’ve got a boyfriend now. He doesn’t like that.”

After class, she packed up her training bag — white, with a black kanji symbol embroidered on the side — and left the gym alone. It was the last time anyone would see her alive.

By dawn, the midsummer sun had risen again. Its warmth bathed the red brick of Ektorp School in gold. Birds chirped over the early bustle of commuters and joggers. But behind the school, in a flowerbed flanked by birch trees and discarded crisp wrappers, a jogger stumbled upon something that didn't belong.

It was Jennifer.

Face pale, eyes closed, body laid out with eerie neatness. Her karate bag was beside her, unzipped. There were no visible signs of a struggle. Only a red mark on her neck, and the kanji symbol inked on her forearm — the same one stitched on her bag.

The jogger dialled emergency services with trembling hands.

The Black Belt and the Bottle

The call came into Nacka police station at 06:59. Within half an hour, the area was cordoned off. By mid-morning, forensic technicians were combing the flowerbed with gloved hands, photographing blades of grass, plastic wrappers, and the worn fabric of Jennifer’s training bag.

Inspector Karin Wallström stood quietly over the scene, arms folded. She’d seen bodies before. But this one… this was clean. Controlled. Almost reverent in how it had been staged.

By 10 a.m., suspicion had narrowed to a single person: the last person to see Jennifer alive — her trainer, Manolis Karagiannis. Calls to his mobile rang out. His flat in Tärnö was locked and empty. His neighbours hadn’t seen him since the night before.

It wasn’t until 10:22 p.m. that the mystery cracked open. Police received a call from a mobile phone registered to Manolis. The voice on the other end was slurred and barely audible.

“I drank something… it’s poison… I’m going to die.”

Officers traced the signal to a cottage outside Kristineberg. When they broke in, they found Manolis unconscious on the floor, with a handwritten note laid across his chest. He had downed a bottle of antifreeze. On the table beside him were torn photographs of Jennifer and a suicide note written in Greek and Swedish.

“I loved her. I didn’t mean to hurt her.”

He survived. Barely.

When questioned in hospital, Manolis claimed Jennifer had asked him to meet after training. That she’d "been confused." That she’d "wanted comfort." But forensic evidence — and later, a series of damning text messages — told another story.

Jennifer had told him she was ending their coaching relationship. That she was in love with someone else. That she no longer felt safe.

He’d begged her to come for a drive. When she refused, he followed her. And when she turned her back — maybe to leave, maybe to make a final point — he strangled her with his bare hands.

No weapon. No fight. Just a moment of lethal obsession.

When the trial began months later, the prosecution painted a portrait of a respected man who had become consumed by jealousy. A man who couldn't accept being left behind.

He was sentenced to 10 years in prison. But Jennifer’s family felt justice had barely touched the surface.

“She trusted him,” her mother, Dagmar Wallin, later said. “He was supposed to protect her. Not kill her.”

The Courtroom and the Silence

The autumn wind swept through Stockholm with a bite. Leaves, dry and ochre-red, scattered across the steps of Stockholm District Court. Inside, the air was stiff with tension. Cameras had been barred, but still the hallway buzzed with reporters, sketch artists, and quiet murmurs from a shaken public.

Jennifer Andersson’s family sat in the front row of the gallery. Her mother, Dagmar, dressed in black and holding a small framed photo of Jennifer in her karate gi, barely looked up as the defendant was led in.

Manolis Karagiannis was thinner now. His skin had the waxy tone of someone recently hospitalised. But his eyes — dark and unreadable — swept the courtroom before settling briefly on the prosecution table, then downward.

The lead prosecutor, Tora Holst, stood to open the case. “This is a betrayal, not only of trust, but of power. A teacher and role model turned predator. A man who should have been safeguarding her potential instead destroyed it.”

Over the following days, the court heard a harrowing account of control and obsession. Witnesses included fellow students, parents from the junior group, and Jennifer’s boyfriend — who had met her only weeks before her death.

“We were at Grinda together. A school trip,” he said, his voice barely audible. “She told me she had to be careful. That Manolis didn’t like it when she smiled too much around other boys.”

The most damning evidence, however, came in digital form: a string of text messages recovered from Manolis’ mobile. Some were pleading, others angry. One read:

“If you quit the team, I will not be responsible for what happens.”

Forensic psychiatrists testified that Manolis showed signs of narcissistic obsession — but that he was not psychotic. “He knew what he was doing. He calculated it. He placed her body with intention.”

The defence attempted to argue a moment of madness, a confused teacher overwhelmed by emotion. But the court didn’t buy it. The methodical nature of the act — the positioning of the body, the suicide note, the delay in calling for help — all pointed to something far more premeditated.

On February 19, 2002, the verdict was handed down.
Ten years in prison — the maximum allowed under Swedish sentencing at the time for a manslaughter conviction with mitigating psychological factors.

Dagmar Wallin stood outside the courtroom after the sentencing, facing a wall of microphones. “Ten years,” she said. “He gets a future. My daughter doesn’t.”

A Mother’s Mission

In the years that followed, Dagmar became Jennifer’s voice. She published a book, Älskade Jennifer (Beloved Jennifer), a raw and intimate memoir of grief and fury. She campaigned for stricter sentencing in crimes where a position of trust is exploited. And she refused to let her daughter’s memory fade into a simple statistic.

At Jennifer’s memorial service, held at the church in Gustavsberg where she had been baptised, friends gathered in white belts and floral dresses. The artist Denise “DeDe” Lopez — a close family friend — performed a song she had written especially for the ceremony. Last to Know was played with home videos of Jennifer in the background: laughing, sparring, twirling her belt like a ribbon in the sun.

“She was young and happy,
Now an angel in heaven,
We could never take her soul away…”

It became a minor hit in Sweden, a soft anthem for grief and justice. DeDe told Aftonbladet, “We won’t let her be forgotten. Not now, not ever.”

Manolis was released from prison in 2005. Quietly, under the radar, he moved into a modest cottage near Kristineberg. He was to start life over — a free man, legally. But freedom, it seemed, was fleeting.

Later that autumn, he was found dead — shot outside a small shop in Bromma. The killing was precise, execution-style. No witnesses. No cameras. No arrests.

At first, rumours spread: was it a revenge killing? An act of vigilante justice?

Police later speculated it may have been an underworld debt or an unrelated criminal conflict. But the public, and Jennifer’s community, remained unconvinced. In the eyes of many, justice had been finalised — just not in the courtroom.

The murder of Jennifer Andersson is still remembered in Swedish media as one of the country’s most chilling examples of teacher-student obsession turned fatal.

And every midsummer, in the suburbs of Nacka, her name is still spoken. In whispers. In warnings. In grief.