The jury in St. Charles County deliberated for less than three hours yesterday; Baumruk will be formally sentenced on March 19.
He previously was convicted of murder by a St. Louis County jury in 2001 and sentenced to die. But the Missouri Supreme Court threw out that conviction, saying the trial should have been moved out of the same courthouse where the shooting occurred.
The sequestered jury heard testimony from several of Baumruk's relatives, including Mary Baumruk's two daughters, during the penalty phase.
The jury on Saturday found the former Seattle man guilty of the shootings during the couple's divorce hearing in 1992.
Baumruk, 67, was convicted of first-degree murder in the killing of his Mary Baumruk at the St. Louis County Courthouse. Jurors ignored pleas by defense attorneys Robert Steele and David Kenyon to find Baumruk not guilty by reason of insanity.
The two attorneys argued during the weeklong trial that Baumruk suffered from "delusional disorder" and couldn't appreciate the wrongfulness of his actions.
There was little question that he fired the fatal shots. Several people witnessed the shooting, and it was captured on audiotape.
St. Louis County prosecutors J.B. Lasater and Dean Waldemer told jurors that Baumruk knew what he was doing. They said he bought two guns in January 1992 and told co-workers at Boeing Co. that he would "kill them all" at the couple's hearing, including his wife, the attorneys and the judge.
They said Baumruk packed the guns in a suitcase for the flight from Seattle to St. Louis. For the bus ride to the courthouse, they said he put the pistols in his briefcase and put ammunition in his coat pockets.
As the hearing began in 1992, Baumruk pulled out one of the pistols and began shooting.
After the Missouri Supreme Court ordered a re-trial, Baumruk was not determined mentally fit for his second trial until August 2005.© Copyright 2016, St. Louis Public Radio