Olga Hepnarová was born on June 30, 1951, in Prague, Czechoslovakia. Her parents were Czech; her father worked as a bank clerk, and her mother was a dentist. As a child, she was considered average. However, as she grew older, she faced difficulties that affected her mental health. She had trouble communicating with others, which led to psychiatric problems.

In 1964, when she was just 13 years old, Olga attempted to take her own life by overdosing on medication. This act led to her spending a year in a psychiatric hospital in Opařany. During her time there, she experienced abuse and harsh treatment after trying to escape. The specialists at the hospital did not diagnose her with any mental illness but noted that she was "neither homosexual, nor heterosexual."

After leaving the hospital, Olga tried various jobs. She was trained as a bookbinder in Prague but generally struggled to keep jobs. She often got fired shortly after being hired. She eventually worked as a truck driver. Over time, she grew distant from her family, particularly her father and older sister.

Olga purchased a cabin in the village of Oleško. This became her home for some time, and she used it as a base to commute to work. Later, she sold the cabin. With the money she received, she bought a Trabant car. 

On the morning of 7 August 1970, Olga Hepnarová attempted to set fire to her family's holiday home in Zábrodí. She poured gasoline on the door of the living area, hoping to destroy the entire property. At that time, her sister and two elderly tenants were asleep inside. Thankfully, they woke up and extinguished the flames before much damage was done, which only amounted to 50 Kčs. Hepnarová later confessed to this act during a psychiatric examination in 1973. She revealed that her motive was linked to money disputes between her parents.

About three years later, on 10 July 1973, Hepnarová executed a planned truck attack in Prague. She had thought about her actions for six months and wanted to ensure that her act would be remembered. Before the attack, she wrote a letter to two newspapers, explaining her motivations and feelings of hatred towards society.

On the day of the attack, she drove a Praga RN truck onto the sidewalk at Strossmayer Square, where about 25 people were waiting for a tram. Hepnarová deliberately rammed her truck into the crowd, which resulted in immediate casualties. Three people died on the scene, and others succumbed to their injuries in the following days. Twelve additional individuals were injured but survived the event.

Witnesses initially thought Hepnarová had lost control of the vehicle, but she quickly admitted her intent. During the investigation, she confirmed that she aimed to kill as many people as possible and expressed no remorse for her actions.

Following her arrest, Hepnarová was tried and found guilty of multiple counts of murder. On 6 April 1974, she was sentenced to death. Despite several psychiatric evaluations, which concluded she was criminally responsible, her request for a pardon was denied.

Hepnarová was executed by hanging on 12 March 1975 in Pankrác Prison. She became the last woman to be executed in Czechoslovakia. Reports vary regarding her demeanor before her execution, with some saying she remained calm while others described her as hysterical and begging for her life.