CENTERVILLE - Murders in Piatt County are few and far between.

So when Gary Shaffer, the Cerro Gordo police chief at the time, heard in 1981 that a relative had fatally shot his neighbor near Centerville, he had to investigate.

The fact that the murder had been committed 93 years earlier did not slow Shaffer down one bit.

When Shaffer began researching his family history, his father told him about the 1888 murder of Adam Spear, a wealthy farmer, by James Mounce, a sawmill operator who had been feuding with him. Shaffer's father said Mounce had a branch on the family tree.

Shaffer immediately wanted to find out all he could about his family's "black sheep.''

"As a good police officer, I followed up,'' said Shaffer, who retired as police chief in 2004. "Like a good hound dog, my ears picked up, and I went on the hunt.''

He contacted a great-uncle, who lived near Bloomington, who had known Mounce. Mounce had lived until 1940, long after his release from prison.

"It was a mystery, a curiosity, something out of the norm,'' Shaffer recalled. "I wanted to know more about it.''

Shaffer pored over records at the county courthouse and newspaper archives at Monticello's Allerton Library.

While Shaffer, a distant relative of the murderer, had devoted his research to Piatt County sources, Sue Ridgley, a distant relative of the murder victim, began investigating sources in Macon County.

The trial, which involved well-known attorneys from across Illinois, was covered by Decatur newspapers. Mounce was held in a Decatur jail, to prevent his lynching.

Sue Ridgley, a retired Decatur School District teacher, began looking into her family's roots this past winter, after she broke her shoulder. Her husband's great-grandmother, Fannie Ridgley, was Adam Spear's daughter. She was an 18-year-old married woman when she testified at the trial that she was reading to her father shortly before he was killed.

While researching on the Internet, Sue Ridgley discovered that a Mounce descendant was advertising an annual family reunion.

When she e-mailed the woman in Texas, Ridgley received a response: "You ought to talk to my cousin. He is in a town in Illinois, Cerro Gordo. Is that close to you?''

Ridgley contacted that cousin, Shaffer, who told her about his research adventures. The representatives of the two feuding families decided to work together.

"We're no longer feuding,'' Ridgley said. "The feud is apparently over.''

The two historical sleuths transcribed dozens of newspaper articles on the Mounce trial and its aftermath, from The Decatur Republican, The Piatt County Herald, The Piatt Independent, Decatur Daily Dispatch and Monticello Bulletin.

Ridgley compiled the transcripts into a 54-page looseleaf notebook, entitled "Murder at Centerville: The People vs. James Mounce for the killing of Adam Spear.'' The book is illustrated with photos from the family collections of Ridgley and Shaffer.

Centerville is a tiny town in northern Piatt County, which was larger and quite prosperous 120 years ago.

Besides bringing to life the trial, which included about 100 witnesses, the book also sheds light on judicial and cultural practices of that day.