A Fitness Tracker Helped Police Pinpoint An Unlikely Killer in California

Karen Navarra was a beloved coworker who never called in sick to work. So when she didn’t show up for her shift as a pharmacy technician at Regional Medical Center in San Jose, California, her coworker Amber Ashfaq was frantic.

The women had worked together for 27 years and had forged a special relationship after Karen had taken Amber, a recent immigrant to the United States, under her wing.

On Sept. 13, 2018, Amber drove to Karen’s house after her friend missed work a second time and didn’t answer her phone calls or text messages.

When she arrived at Karen’s house, Amber found the door unlocked and discovered her friend’s lifeless, discolored body in a dining chair. Blood was splattered across the table and the kitchen. She immediately called 911.

A Strange Crime Scene

Homicide investigators walked through the home searching for clues about what had happened to Karen. She had deep head and neck wounds, and she was still clutching a knife in her hand. It was obvious she had been dead for several days. Police briefly wondered if her wounds were self-inflicted.

The veteran investigators noted that the home appeared disheveled—there were dresser drawers pulled out and dropped on the floor. Lots of items were disturbed, but they quickly realized nothing had been taken and none of Karen’s valuables had even been bothered. Whoever had killed Karen tried to stage the scene to look like a burglary.

Police also noted that there was a plate with four pieces of pizza on the counter near Karen’s body. They believed she had planned on sharing the pizza with somebody. Who had been there?

Digital Bread Crumbs

Karen was wearing a fitness tracker on her wrist, which tracked health metrics such as heart rate, activity, and sleep. Authorities knew immediately they needed a search warrant for that data to see if it could help them narrow down when Karen was killed.

As they waited on the fitness data, they processed other evidence—a receipt from a local grocery store established that Karen had gone shopping on Sept. 7. Video surveillance showed her calmly entering the store, shopping for groceries, and then paying and driving away.

Police went to speak to Karen’s mother and stepfather, who lived near Karen’s home. Her 90-year-old stepfather, Anthony Aiello, told investigators that he had taken pizza and cookies to Karen on the afternoon of Sept. 8, and that Karen mentioned getting together with friends. He told the police that he saw Karen drive by their home later that day and that she had someone else in the car with her.

There was just one problem—there was only one way in and out of the neighborhood where Karen and her parents lived. A neighbor’s security camera trained on the road didn’t capture Karen’s car coming or going at all on Sept. 8.

As data from the fitness tracker comes in, authorities realize that Karen’s killer is the last person they ever suspected.

Find out who police charged for Karen’s murder on Caught in the Net “Heart Rate & Time” on ID GO and watch new episodes on ID, Mondays 10/9c.