After Confederate forces were driven from Missouri in early 1862, the Civil War in the state quickly devolved mainly into a vicious brand of guerrilla warfare marked by robbery, sabotage, and murder. Atrocities were committed by both sides, but bands of Confederate-allied guerrillas, in particular, roamed the countryside. The bands sometimes preyed on civilians, but they especially targeted Union soldiers who happened to be separated from their units or former Union soldiers who'd returned to their homes.
One unfortunate Union lieutenant named Miller found this out the hard way when he took a Sunday leave on April 28, 1862, to court a young woman in Barry County. The officer was spotted by noted guerrilla Hugh McBride and a companion named Smith Crim. The two men watched as Miller hitched his horse outside the girl's home, and then they crept up to the dwelling, When the two burst inside, McBride covered the officer with a shotgun and took him prisoner.
The two guerrillas took Miller some distance into the woods before McBride decided that he had to die. McBride ordered Crim to shoot the lieutenant, but Crim refused. An angry McBride then unloaded one of the barrels of his gun into Miller.
Crim, though, not McBride, was the one who suffered the consequences. He was arrested not long afterwards by Union forces and tried by military commission at Springfield in late September 1862. Found guilty of murder and violating the laws of war, Crim was sentenced to die by firing squad.
The sentence, however, was not carried out, at least not immediately. In early 1863, Crim was transported to St. Louis and lodged in the Gratiot Street Prison.
Sources: St. Louis Daily Missouri Republican; Matthew Stith, Extreme Civil War.