It was a century-old mystery about who was buried in a Lawrence grave.

Now, a new documentary details the work of two University of Colorado professors as they exhumed a body in 2006 at Oak Hill Cemetery to try to determine that John Hillmon was buried there.

Uncovering the identity of the person buried in the unmarked grave from the late 1800s was part of a long insurance fraud battle that generated six trials and a landmark U.S. Supreme Court decision on admissible hearsay evidence.

CU anthropology professor Dennis Van Gerven and law professor Marianne Wesson said their team was unable to reach a conclusion during a DNA analysis that Hillmon was buried there, rather than another man, Frederick Adolph Walters.

But Van Gerven later performed an analysis of photographs of the corpse and the two men. He determined that point-by-point comparisons of standard anatomical features matched the corpse with Hillmon and not Walters.

“Ironically, we ended up solving the puzzle with what we started with,” Van Gerven said.

The case had a lengthy history that dated to when Hillmon left his Lawrence home in 1879 to find ranch land. His companion, named John Brown, later showed up in Medicine Lodge and said he accidentally shot Hillmon.

Insurance companies suspected fraud and said they believed Walters was actually killed instead and passed off as Hillmon so that Hillmon and Brown could collect on a $25,000 insurance policy. The legal wrangling went on for years, and it included a famous Supreme Court decision that created an exception to the hearsay rule. It permitted a letter from Walters’ fiancee to be admitted into evidence. The letter stated his intentions to travel with Hillmon.

The Supreme Court ruled in favor of the insurance companies in 1892. Wesson, who taught her law students about the case, was skeptical of the Supreme Court decision and decided to pursue the mystery at the gravesite.

Van Gerven and Wesson returned in 2007 to Lawrence and placed a headstone with Hillmon’s name on the grave.

Van Gerven said he hopes to soon make the documentary available to Lawrence-area residents — including District Judge Paula Martin, who approved the exhumation — so they can learn more about how his team treated the remains during the exhumation process.

“I don’t want people in the community to believe that this was done frivolously,” Van Gerven said.

In Boulder, a public viewing of the documentary by CU associate film professor Ernesto Acevedo-Munoz is scheduled for Thursday. Wesson is working on a book about the case.