Jurors didn't buy it when 27-year-old Mary Weishar insisted a masked man had killed her husband during a robbery attempt at their southern Minnesota shanty in Kasota. He'd been shot twice with a .32-caliber revolver.

Nearly 140 years later, great-great-grandson Bruce Taber found himself staring at the two bullets. He'd been digging into his family's twisted past at the Minnesota History Center when a research aide gave him a small envelope that had been tucked in court records.

"I sat in the chair about five minutes before I opened the envelope and found the two slugs," Taber said. "It kind of blew me away."

As for who blew away Frank Weishar on April 11, 1880, jurors needed only three hours to convict his wife, done in by a 14-year-old witness and a bullet-ridden breadboard. Mary was found guilty of first-degree murder and sentenced to life at Stillwater State Prison, but wound up serving not quite nine years after Gov. Lucius Hubbard commuted her sentence — allowing her release for what prison records called "good conduct." She'd taken care of the prison warden's house during her incarceration.

Public reaction to the murder skewed toward sympathy for the shooter.

"If she did kill him," the St. Peter Times reported, "she simply put out of existence a notorious thief, for doing which she is entitled to the thanks of all mankind."

Mary Weishar was born Samantha Ferrier in Pennsylvania in 1853 and moved to Minnesota at the age of 5 with a notorious older brother known for stealing horses and wheat.

"The lot of this woman from infancy has been unhappy," the St. Paul Globe reported upon her conviction, saying she was "yet a girl" when she "drudged her way to womanhood" and married Frank — "a stolid, mercenary German, much older than herself" — because she needed a home. They settled in Kasota, just south of St. Peter, and raised four children.

"The marriage was neither the result of affinity or love," according to the Globe. They lived "in the most abject squalor and poverty."

At the trial, 14-year-old Lizzie Menton testified Mary told her that she planned to kill her husband, and urged the teenager to join her in an unnamed city where they could escape their dreary lives for riches earned in a brothel. Menton testified that Weishar had shown her the gun and tested it out on a board used for kneading bread. Authorities found the board with a bullet hole to corroborate her story.

"It is sufficient to say that she was convicted on the testimony" of Menton, according to the Le Sueur Sentinel, which reported that Lizzie "testified in a singularly straight-forward manner … unshaken by a sharp cross-examination."

Taber's extensive research shows that Lizzie also came from some suspect surroundings. Two years before the Weishar murder, members of the Menton family crashed a party in St. Peter with clubs, fatally fracturing the skull of the host who hadn't invited them.

Taber, 65, who lives in Excelsior and works in the circulation department of the Star Tribune, first learned about his ancestor's criminal past about 160 miles north of the scene of the crime. He was visiting family graves on a Memorial Day in tiny Clotho, Minn., with his father. Mary Weishar remarried a much younger man named George Murch in 1890 shortly after after her release from Stillwater.

Taber asked his father why the name etched on his great-great-grandmother's tombstone was different than other ancestors, "and he told me there was a rumor that Grandma shot and killed Grandpa."

That sent Taber on a deep dive through digitized newspaper clippings and government records — including the discovery of the two bullets.

Perhaps the most amazing result of Taber's research centers around his great-grandfather and the ill-fated couple's oldest child, Frank Jr. He was 10 when his mother killed his father, but despite that trauma the younger Frank, who spelled his last name Weishair, became a leading citizen.

He founded the Todd County Tribune, farmed successfully, sired 13 kids, became active in Nonpartisan League politics, served the township and school board, and was an officer at the local creamery. When he died at 60 in 1930, 600 people attended his funeral.

"I couldn't do all that in five lifetimes," Taber said. "He was at the other end of the spectrum than his parents and It shows that in one generation, all bad things can be reversed."

Mary, his great-great grandmother and a convicted murderer, had two more kids with Murch, one of whom died giving birth and the other in a car accident. She died at 67 in a 1920 kitchen fire when her dress caught on fire, Taber said. Frank Jr. had her buried in the family plot in Clotho, where Taber first learned of his family's notorious history.

Curt Brown's tales about Minnesota's history appear each Sunday. Readers can send him ideas and suggestions at mnhistory@startribune.com. His latest book looks at 1918 Minnesota, when flu, war and fires converged: strib.mn/MN1918.