The Case:
In 1996, a young mother of two was discovered brutally murdered in a town called Noosa Heads, on the Queensland coast. Her body was dumped in a park among flowering wattle trees, native to Australia. The victim’s car turned up outside a man’s home in the nearby town of Gympie, inland from Noosa. Flower petals and plant debris littered the car’s interior. When police questioned the owner of the house, he outright denied having recently been in Noosa or driving the victim’s car. He did admit that the previous day he had walked on a path in Gympie where wattle trees were common. Though the police had their suspicions about the man, they had no hard evidence to tie him to the crime.
The police turned to Dr. Milne in the hope that she would shed some light on the case with regard to the plant matter. She observed that the wattle trees in Noosa are of a different species than those in Gympie and generally flower at a different time. She analyzed pollen samples from the two species at each location and identified their “pollen print.” She then examined pollen from the flowers that were found in and on the victim’s car, as well as samples vacuumed up from the car’s upholstery and lifted from the suspect’s clothing.
Dr. Milne’s analysis revealed that all of the flowers were indeed from Noosa, not Gympie, and that most of the pollen in the car and on the suspect’s clothing was also from Noosa — and a perfect match. This evidence was used to link the suspect to the scene of the crime. He was arrested and brought to trial, where he was convicted of the murder and sentenced to life imprisonment.