Apple Watch heart monitoring data is playing a major role in an Australian murder case, as prosecutors used 57-year-old Myrna Nilsson’s activity tracking history to determine the timeline of her final moments. According to the Daily Mail, the Apple Watch data contradicted a story told by her 26-year-old daughter, Caroline Nilsson, who has now been charged with the killing.

The mother’s gruesome murder took place in September 2016 at her Adelaide home, and she was found bludgeoned to death and bound with tape in the street. At the time, Caroline Nilsson told police that a group of men had attacked her mother after a road rage incident.

However, a forensic expert checked data from the mother’s Apple Watch, which showed a burst of heavy activity, then a period of less activity, and ultimately the cessation of heart rate recording. In addition to being consistent with an “ambush-type” attack and the subsequent loss of consciousness and life, the data established a seven-minute window between attack and death — 6:38 p.m. to 6:45 p.m.

Between the activity and time data, the Watch undermined Caroline’s assertion that her mother had argued with her attackers for 20 minutes and then continued to use her phone until 7:13 p.m. — all while allegedly tied up and under attacked from the intruders. Prosecutors determined that her story was demonstrably false and concluded that the home invasion crime scene had been staged.

Australian police arrested Caroline more than a year after the crime and charged her with Myrna’s murder. The daughter will return to court on June 13 and, according to her attorney, will deny the charges.