A year-old girl, Brenda Spencer, who lived in a house across the street from the school, was convicted of the shootings. Charged as an adult, she pleaded guilty to two counts of murder and assault with a deadly weapon , resulting in her being sentenced to life in prison with a chance of parole after 25 years. As of , she is still in prison. Brenda Spencer is often regarded as the first modern school shooter in the United States.
A reporter reached her by phone while she was still in the house after the shooting, and asked her why she committed the crime. She reportedly answered: "I don't like Mondays. This livens up the day. After Dorothy found out her husband had been cheating on her with multiple women, she filed for divorce in January After her parents separated, Brenda allegedly lived in poverty with her father; both father and daughter slept on a single mattress on the living room floor in a house strewn with empty bottles from alcoholic drinks.
Aged 16 at the time of the shooting, she was 5'2" cm and had bright red hair. Acquaintances said Spencer expressed hostility toward policemen, had spoken about shooting one, and had talked of doing something big to get on television. She attended Patrick Henry High School , where one teacher recalled frequently inquiring if she was awake in class. Later, during tests while she was in custody, it was discovered Spencer had an injury to one of the temporal lobes of her brain.
It was attributed to an accident on her bicycle. Spencer described herself as a "radical" and referred to policemen as "pigs", exclaiming "All right! In early , staff at a facility for problem students, into which Spencer had been referred for truancy , informed her parents that she was suicidal. That summer, Spencer, who was known to hunt birds in the neighborhood, was arrested for shooting out the windows of Grover Cleveland Elementary with a BB gun and for burglary.
In December prior to the shooting , while still on probation for breaking into the school, a psychiatric evaluation arranged by her probation officer recommended that Spencer be admitted to a mental hospital for depression , but her father refused to give permission.
