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How MoBot used plant DNA to convict a Missouri killer

Boone County Prosecuting Attorney's Office
Photo evidence of Joe Elledge’s hiking boot caked with mud. The boot hid 12 different types of vegetation, including juniper needles.

Lawyers, judges and fans of true crime stories are familiar with the concept of "planting evidence," but in a Missouri murder case recently featured in an episode of "48 Hours," the evidence was — plants.

Kristina DeYong
Missouri Botanical Garden
CBS' "48 Hours" interviewed plant conservation geneticist Christy Edwards.

Conservation geneticist Christy Edwards and her colleagues at the Missouri Botanical Garden used their scientific skills that are normally reserved for researching and saving rare and endangered plant species to help build a case against Joseph Elledge for the 2019 slaying of his wife, Mengqi Ji, in Columbia, Missouri.

The "48 Hours" episode details the intricate process of collecting plant matter from the site where Ji’s remains were discovered by a hiker almost two years after her disappearance. For Edwards and her team, it all started with juniper needles stuck on a muddy boot.

“We were certainly skeptical whether we would be able to get any usable DNA out of the juniper needles. It's kind of one of those things where you just have to try it and see,” Edwards said on St. Louis on the Air. “When we went out to the [burial] site, it was a juniper grove. … That was kind of our first clue that … there could be some matching individuals. But we wanted to be able to match the DNA to specific trees.”

The MoBot scientists who worked on the case didn’t have to change how they analyzed plant DNA to make a match, and they ultimately made a match that was critical in placing Ji’s husband at the burial site.

“The whole situation [was] so sad. It's not something I normally work with,” Edwards said. “I’m used to working with endangered plants, you know, not murder. So it was hard … [and] in the long run we were able to help get justice for her family [and] I think that feels good.”

A jury convicted Joseph Elledge of second-degree murder in 2021.

To learn more about how Christy Edwards and geneticists at the Missouri Botanical Garden used plant DNA to solve Mengqi Ji’s killing, listen to St. Louis on the Air on Apple Podcast, Spotify, Google Podcast, Stitcher or by clicking the play button below.

How MoBot used plant DNA to convict a Missouri killer

St. Louis on the Air” brings you the stories of St. Louis and the people who live, work and create in our region. The show is produced by Miya Norfleet, Emily Woodbury, Danny Wicentowski, Elaine Cha and Alex Heuer. Avery Rogers is our production assistant. The audio engineer is Aaron Doerr. Send questions and comments about this story to talk@stlpr.org.

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