The dark-pink slice of the banding around her underwear was one of 154 pieces, or “cuttings”, that Krey took from the underwear to be tested for the presence of DNA, Lohmar said.

Lohmar said some people in the forensic science community might “gasp” at the number of samples St. Charles scientists analyzed; most labs, he said, only allow scientists to examine a handful of “cuttings.” But Hampton did not put any limits on how many samples Frey could analyze or the amount of time it took, Lohmar said.

It wasn’t until mid-2017 that technology advanced enough to prevent clothing dye like on the underwear from making it difficult to extract reliable DNA samples, Lohmar said. Hampton, Frey and their lab’s technical leader, Daniel Fahnestick, also knew that the way in which DNA is considered a “match” to a person was expanding, so they waited until both of those advances developed enough to re-examine all of the evidence in the case, Lohmar said.

Lohmar said the forensic team “pumped the brakes” a few times during its research, knowing these advances were coming and not wanting to blow their chances by rendering samples unusable for future testing.

The team was in the final phase of re-testing all of the evidence when they got the match, Lohmar said.