On a frigid December morning in 1984, the quiet, snowy landscape of Grafton, Wisconsin, was shattered by a horrific discovery. A local resident, walking along a remote driveway, stumbled upon the body of a young woman. She was partially unclothed, and it was clear she had been the victim of a brutal attack. The young woman was 18-year-old Tracy Hammerberg, and the tragic incident that ended her life would become a haunting cold case that would grip the community for more than three decades.
Tracy was a high school senior, described by those who knew her as a “social butterfly”—a friendly and well-liked girl who loved being around people. However, her life at home was far from perfect. She had a strained and difficult relationship with her stepfather, a reality that led her to spend more time away from the house and, at times, led her down a dangerous path involving substance use.
Despite these struggles, Tracy was determined to build a better future. She had a loving boyfriend, worked a part-time babysitting job to save money, and dreamed of graduating and moving to another state to start fresh.
On the night of December 14, 1984, Tracy was at a party with friends. Around 12:30 AM, she decided to walk the three miles back to her home. Though a friend offered her a ride in the freezing cold, she politely declined, saying the walk wasn’t that far for her. It was the last time she was seen alive. The next morning, her body was found.
The initial investigation was intense but frustrating. The crime scene told a story of a violent struggle. Tracy had been subjected to a horrific physical and sexual violation, and the cause of her passing was a severe fracture to her skull.
Investigators found crucial evidence in the snow: tire tracks, a pack of Marlboro cigarettes, and, most importantly, a sample of male DNA on her body and under her fingernails, a clear sign that she had fought back fiercely against her attacker. The location where she was found, far from her walking route home, suggested she had been taken there by car.
Detectives worked tirelessly, questioning everyone at the party and expanding their search to Tracy’s wider circle of friends. They quickly cleared her boyfriend, her stepfather, and even the sons of the property owner where she was found. In a massive effort, they collected over 230 DNA samples from local men, hoping for a match.
But none came. With no leads and no matches, the trail went cold. Years turned into decades. Tracy’s case became a painful, unanswered question hanging over the small town.
Then, in 2019, everything changed. With incredible advancements in forensic science, the Ozaukee County Sheriff’s Office reopened Tracy’s case. The original DNA evidence, carefully preserved for 35 years, was sent to a specialized lab.
Using genetic genealogy—a revolutionary technique that compares crime scene DNA to profiles in public genealogy databases—they finally got a hit. The DNA was a partial match to a second cousin of the unknown perpetrator.
This was the breakthrough investigators had been waiting for. Using that familial link, they painstakingly built out a massive family tree, identifying common ancestors and tracing their descendants.
They narrowed the possibilities down to two brothers who had lived in the Grafton area in 1984: Eugene and Philip Cross. Philip had passed away in 2012 from a drug overdose, but his brother Eugene was still alive. Police obtained a DNA sample from the surviving brother and confirmed that the DNA from the crime scene belonged to his late sibling, Philip Cross.
After 35 years, Tracy’s attacker finally had a name. Philip Cross was 21 at the time of the incident and was not a stranger to Tracy; they had attended the same school and even ridden the same bus. He had a dark reputation around town as an aggressive and violent individual with a long criminal record that included car theft, drug offenses, and even making and detonating homemade bombs at a school.
He had been released from jail just months before the incident involving Tracy. Chillingly, another woman later came forward to report that Philip had attempted to assault her in his car after Tracy’s passing, but he was never charged.
The resolution was bittersweet. The mystery was solved, but justice, in the traditional sense, could never be served. Philip Cross lived as a free man for 28 years after he ended Tracy’s life, never facing a court for his horrific crime.
In a final, heartbreaking twist, Tracy’s own mother, Judy, passed away before she could ever learn the truth about what happened to her daughter, a truth she had desperately sought for nearly the rest of her life.
