The science in Sean Phillips' shoe dirt

EAST LANSING, Mich. (WOOD) - Dirt and plant life met in a crime scene investigation that ended with the conviction of Sean Phillips for the unlawful imprisonment of his 4-month-old daughter Katherine.

Police confiscated a pair of Phillips' shoes when they searched his house in the aftermath of Baby Kate's disappearance on June 29, 2011. Those shoes had dirt and debris on them.

Investigators enlisted the help of Michigan State University plant biology professors who provided some answers.

Soil science professor James Crum told police the dirt likely came from some windswept area near the Lake Michigan shoreline. His colleagues, Professor Frank Telewski and graduate student Peter Howie Carrington, analyzed seeds found on those shoes.

The idea was to help determine where Phillips could have been -- and not been -- in a two-hour window that particular afternoon. Prosecutors claimed the evidence showed Phillips was in a marsh or wetlands area.

The kind of work Crum and Telewski do in the plant lab isn't much different from the kind of work a detective investigating a crime.

"You want to take careful notes, careful observations of what's around you, because that very little thing that you might miss may be the key to answering your research question," Telewski told 24 Hour News 8. "And I think the same thing is true of detectives when you're at a crime scene."

It's unclear what, if any influence the dirt and seed evidence had on the jury.

But it may help eventually find the little girl.

Telewski and Carrington continue analyzing the seeds found on Phillip' shoes.

Using Crum's soil expertise, they hope to further narrow down where those seeds could sprout. Carrington is actually growing those seeds in the lab.

"If we can germinate a plant and bring it to flower, then our chances are really centering in on what species were involved and therefore what places can be ruled out become even more auspicious," said Carrington.

The problem for the people still looking for Kate is there's an infinite number of places to search.

The MSU professors hope to narrow down areas where Phillips and possibly his daughter were that day, not only by identifying where the plants grow, but also where Philips was around that day.

"You try to narrow down those habitats  to within the time frame," Telewski said, how far you can travel from point A to point B and make the locations that were mentioned in the case."

They then hope to match the plants in a potential search area with plants grown from the seeds at MSU.

"There's going to be more than just one locale," he said. "But if you can narrow it down from hundred of locales to 10 or  a handful, a half-a-dozen of locales, that would really help the searchers.

"I hope that we are able to resolve this case, whatever the outcome might be."