The story about the half-Jewish Van Lier is startling. She came from a wealthy family and lived next door to the Rietveld Schröder House. In 1940 she started studying law at Utrecht University. She joined the student corps and a student resistance group. In 1943 she infiltrated the NSB and Wehrmacht as a 22-year-old and small acts of resistance keep increasing. On September 3, 1943, she shot and killed the Utrecht NSB chief of police Gerard Kerlen near his house on the Willemsplantsoen in Utrecht. She had shadowed him for a long time before that.
A few weeks later, Van Lier was arrested. Shortly afterwards she ended up in Sachsenhausen concentration camp, where she was executed on October 27, 1943.