Murder of Casey Williamson

On July 26, 2002, six-year-old Cassandra "Casey" Lynn Williamson disappeared from her home in Valley Park, St. Louis County, Missouri. She was last seen around 7 a.m. in the kitchen of her home by her father, Ernie Williamson, who alerted family members within minutes of noticing her missing. Local police, St. Louis County deputy sheriffs, FBI agents, and community volunteers conducted an extensive search. Witnesses reported seeing the girl being carried away by a man later identified as 24-year-old Johnny Allen Johnson, a family acquaintance who had attended a barbecue at the Williamson home the previous night and slept on the family's couch.

Johnson was brought in for police questioning. He initially denied involvement but later admitted to taking Casey from her home and killing her at an abandoned glass factory near her home. Williamson's body was subsequently found in a shallow pit less than a mile from her home by a volunteer participating in the search. An autopsy determined she died from blunt force injuries to her head, including skull fractures and brain bruising, along with other injuries to her arms, shoulders, legs, and back. Evidence, including semen found on Johnson's shorts, indicated a sexual assault had occurred. Investigators determined Johnson had attempted to rape Williamson, and when she resisted, he struck her with a brick and a large rock before killing her. He then washed himself in the nearby Meramec River. A memorial for Williamson was held on July 30, 2002, at Twin Oaks Presbyterian Church.

Johnson was charged with kidnapping, attempted rape, and first-degree murder. At trial, he did not deny killing Williamson but argued diminished responsibility due to schizoaffective disorder, supported by testimony from a psychiatrist and his girlfriend. Prosecution psychiatric experts countered that Johnson remained capable of deliberation and that any hallucinations were more likely attributable to drug intoxication. On January 18, 2005, a St. Louis County jury found Johnson guilty of murder, and on March 7, 2005, he was sentenced to death along with three consecutive life sentences for related charges.

Johnson's appeals were rejected by the Missouri Supreme Court in 2006, 2012, and January 2013, and by the U.S. District Court for the Eastern District of Missouri in February 2020. After Missouri's Supreme Court approved his death warrant in April 2023, Johnson pursued last-minute appeals citing incompetency due to schizophrenia; these were rejected by the Missouri Supreme Court, a federal district judge, and ultimately the U.S. Supreme Court, despite a brief stay issued and then overturned by the 8th U.S. Circuit Court of Appeals. Missouri Governor Mike Parson denied a clemency petition. Johnson was executed by lethal injection on August 1, 2023, at the Eastern Reception, Diagnostic and Correctional Center in Bonne Terre, Missouri.

In the aftermath, the abandoned glass factory where the murder occurred was demolished in 2012. Williamson's family established a scholarship and an annual community safety fair in her memory. The case was covered in a 2022 documentary, and family members described the lasting impact of the crime, including substance abuse and mental health struggles among surviving relatives.