The jury reached its verdict without hearing testimony that Uden's current husband, Gerald Uden, confessed last year to murdering his ex-wife and their two young boys in 1980, also with a .22-caliber rifle.
During the weeklong trial, Uden, who is frail and uses a wheelchair, spent two days on the stand testifying that she shot Ronald Holtz, a 25-year-old Vietnam veteran, to defend her 2-year-old daughter Erica when Holtz angrily charged at her and threatened to kill her.
But that claim was contradicted by two of Uden's five grown children, who testified for the prosecution that their mother told them in the late '70s that she killed Holtz in his sleep.
"She just, out of the blue, told me how she got up one night, got a .22, and shot Ron in the head," her son Todd Scott, now 53, told the Cheyenne jury last week. "I don't know why a mother would tell her children she killed somebody."
The jury deliberated for about a day and a half before delivering the verdict against Uden, who now had been living in Chadwick, Missouri.
With reporting by CAITLIN KEATING