Lilie James was stalked by a former short-term partner who "carefully planned" and "rehearsed" his attack before carrying out a "premeditated killing", an inquest into her death has been told.
The 21-year-old was found with serious head injuries in the toilet area of the gym at St Andrew's Cathedral School in Sydney's CBD in October 2023.
Homicide detectives began a search for Paul Thijssen, a 23-year-old Dutch citizen who had been in a brief relationship with her, who was found dead at cliffs at Diamond Bay Reserve in Vaucluse days later.
On the opening day of concurrent inquests into the deaths, counsel assisting Jennifer Single SC said the evidence will establish Ms James was killed in the bathroom with a hammer.
She had ended their brief relationship just before her death.
"The evidence indicates that Paul stalked Lilie, Paul carefully planned his attack, and in the hours before the attack, he rehearsed his attack, making a number of dry runs," Ms Single said.