Heart monitoring data from an Apple Watch is being used as evidence in a murder trial in Australia.

Caroline Nilsson was charged with the murder of her mother-in-law, Myrna Nilsson, 57, at their home in September 2016. Nilsson had been found in the streets by her neighbors, with her hands and face bound with tape.

At the time, Caroline Nilsson told police that her mother-in-law had been attacked by a group of men following a road rage incident. But her story didn’t align with the information the prosecution learned from the victim’s Apple Watch.

Forensic investigators, using the watch’s heart rate data, were able to narrow the moment Myrna Nilsson was attacked to the moment she died in a seven-minute window.

The prosecutor, Carmen Matteo, told the court that the watch’s data showed a high burst of heavy activity — consistent with someone being attacked — to a period of slow activity, which was likely when Myrna Nilsson lost consciousness. The watch stopped recording the heart rate shortly after.

“The prosecution accumulates those timings and the information about energy levels, movement, heart rate, to lead to a conclusion that the deceased must have been attacked at around 6:38 p.m. and had certainly died by 6:45 p.m.,” Matteo said, according to news.com.au.

She added that if the timings were accepted as accurate, Caroline Nilsson’s story that her mother-in-law had argued with her attackers for over 20 minutes does not hold up. The trial returns to court June 13.