Complex sentence: Olga Hepnarová (June 30,1951--March 12,1975) was a Czech mass murderer, who in 1973 killed 8 people with a truck.
Split into simpler sentences: Olga Hepnarová (June 30,1951--March 12,1975) was a Czech mass murderer. In 1973, she killed 8 people with a truck.