Two professors at C.U. Boulder have been helping law enforcement solve crime for decades by studying plants at crime scenes and linking evidence to convict criminals.
Jane Bock and David Norris are both retired botany professors at the University of Colorado Boulder. They've helped law enforcement analyze plants to catch rapists and murderers in lies, often leading to confessions, and even conviction.
"We do two different things," said Norris. "One, we look at stomach contents to determine what the meal that person ate. We can also look at fecal material, we can use that to connect a suspect to a crime scene, particularly rape/homicide cases."
That's not all the professors can do. They can identify different plant ecosystems by looking at the cells from someone's tires or clothing, placing them at the scene of a crime.
"So, if you drive a vehicle into a spot, or you get in that area and mess around with the bushes and come in contact with those plants, there will be remnants of those plants found associated with your vehicle or in your clothing," Norris said.
Different groups of plants only live at certain elevations. Therefore, Norris can provide evidence that a suspect could've been at the scene of a particular crime. The professors used this method to provide evidence in a trial in which a suspect was convicted of rape.
"If they say their vehicle hadn't been in a particular area, and you can show the vehicle had been there based on the plant data, then you've caught them in a lie," Norris said.
Another interesting method, law enforcement once found a body of a woman who had been killed and left in a ditch. The murderer put sunflowers over the body to conceal it. Norris and Bock picked fresh flowers and timed how long it took them to wilt to determine how long the victim had been dead. Prosecutors used that evidence to poke holes in the alibi of a suspect.
The pair wrote a book called Forensic Plant Science to share their knowledge with investigators around the world.