Prosecutors say 48-year-old Susan Hendricks is charged with four counts of murder for the deaths in two neighboring homes Oct. 14.
Investigators said Hendricks was in one of the homes that night. She told deputies her youngest son had been using drugs and was suicidal. Officers found a gun by his body, and Hendricks said he left her a note.
But investigators said it was all staged and her statements were inconsistent with the evidence.
The homes are about five miles outside Liberty, in an area of mixed farms and suburban residences in the state's west.