Device Puts A New Spin On Gathering Evidence

But two Michigan State University professors are hoping a giant sucking sound will signal a revolution in gathering crime evidence.

The Trace Evidence Concentrator will be on display May 14-16 at FRENZY, the Forensic Sciences and Crime Scene Technology Conference and Exposition in Washington, D.C. What started as one professor's idea to clean delicate roots for plant research now promises to quickly unearth minutia that can solve crime.

"Till now, the science of evidence collection has not been accurate," says Jay Siegel, a professor of forensic science and chemistry at MSU. "The old-fashioned way - rummaging through soil or vacuumed material by hand with a magnifying glass - takes hours and isn't efficient. You can sort for days and never see what you want."

The Trace Evidence Concentrator helps police by meticulously separating evidence - hair, fibers, paint chips - from soil or materials vacuumed from a crime scene.

The system has a high-tech name - hydropneumatic elutriation, which includes a high kinetic energy vortex, air displacement and water-borne low energy separation - but looks remarkably similar to the new vacuum cleaners on the market. Materials that police collect are dumped into a stainless steel container. Hundreds of tiny, specifically angled jets of water are shot into the tube, creating a whirlpool.

The system, Siegel said, is based on the idea that material that has less density than the surrounding soil particles will float apart from the dirt. Different filters further separate the remaining evidence, which comes out clean and ready for analysis in minutes rather than hours or days.

Siegel, a nationally recognized expert in evidence collection, said that trace evidence is an important tool in solving crimes. A tiny fiber or chip of paint can be crucial, yet is neglected because collecting that clue can be so difficult. For example, investigators of the Oklahoma City federal building bombing sifted through vast amounts of rubble.

"One problem is that the recent interest in DNA evidence is that often investigators are neglecting other kinds of evidence," Siegel said. "They think if they have DNA, they don't need to do anything else, and that's not right."

The device was born of an unusual marriage of disciplines. Siegel found himself chatting with fellow MSU professor Alvin Smucker, a biophysicist, at a wedding reception. Smucker was telling him about a device he was working on that would carefully remove soil from the delicate nodules of plant roots. They quickly realized the device would have other uses.

Siegel and Smucker hold the patent for the Trace Evidence Concentrator, which is licensed to and marketed by Peak Industries of Dearborn.

"Criminals have had a huge advantage," Smucker said. "Because lab techniques for finding trace evidence are highly laborious, antiquated and controversial."