German officials are using data from Apple’s Health app as evidence in a case involving the rape and murder of a 19-year-old medical student in Freiburg, according to local media [via Motherboard].

The case involves Hussein K., who has been on trial since September over the death of Maria L., according to German news outlet Welt. The defendant allegedly raped and strangled the victim, then dumped her body in a river, according to Deutsche Welle.

Some details in the case have not been clear, including the actual age of Hussein K. There’s also information missing during a specific time frame from the geodata and surveillance video analysis.

Authorities said the defendant refused to hand over the passcode to his iPhone. Officials then turned to a company in Munich to break into the device. While, the entire process of getting inside the iPhone took months, authorities were able to get information from the Health app about what Hussein K. was doing during the day of the murder.

Apple’s Health app came to the iPhone automatically under the iOS 8 update in 2014. The app counts a user’s steps, tracks their sleeping hours and combines health data from the iPhone, Apple Watch, and third-party apps. It also includes the user’s Medical ID, like a person’s blood type and date of birth.

Before reviewing the Health app data, investigators noticed he left the tram at 2:10 a.m., and at 2:46 a.m. his device dialed into a radio cell near the crime scene. After that nothing happened for a long time until 4 a.m., according to Welt.

The Health app recorded information of what the defendant did during the time. The app shows the defendant only took a few steps between those hours. Officials were able to correlate the Health app with the geodata. However, the device showed Hussein K. climbed the stairs twice during that time frame. Investigators believe those were the moments in which Hussein K. dragged the student down to the river bank and climbed back up. Officials also sent an investigator with a similar height as the defendant, along with an iPhone, to the scene. With the investigator’s movement, authorities saw that iPhone information matched with the defendant’s movements on the Health app.

This isn’t the first time health data from a device is used for a criminal investigation. Last October, detectives used information from a Fitbit in a murder case in Connecticut. The device showed the victim walked 1,217 feet after going home following an exercise class, a trajectory much longer than the 125 feet walk the suspect had said in his version of the story.

A study by Rand Corporation shows tech, like fitness trackers and smartphones that contain data on daily activities, will be used by criminal investigators more often. However, the lead author of the study said the legal system is not “fully prepared” to deal with the new technologies, citing people’s rights.