Fitbit Reveals Woman's Time Of Death, Leads To 90-Year-Old Stepfather's Arrest

The stepfather of a deceased California woman was arrested on suspicion of murdering her after data collected from a Fitbit monitor revealed statistics pointed to him being the prime suspect.

The body of Karen Navarra, 67, was discovered in her kitchen slouched on a dining chair, with "gaping laceration" on her neck and wounds on the top of her head, which investigators said were not consistent with self-inflicted wounds. Anthony Aiello, the victim’s 90-year-old stepfather, told the police he had left the house before Navarra’s time of death.

According to case reports obtained by the New York Daily News, Navarra’s wounds were caused by a small hatchet or ax, after which the victim’s body was staged to suggest she had killed herself, as she was clasping a large kitchen knife in her right hand when her body was discovered.

She was also wearing a Fitbit Alta at the time of her death. Data from the fitness device, which measured a person’s heart rate and the number of steps taken during the day, showed a significant spike in her heart rate at 3:20 p.m. local time (6:20 p.m. EDT) on the day of her death followed by a rapid slowing, the document said. The monitor stopped registering heart rate data that day at 3:28 p.m. local time (6:28 p.m. EDT).

Aiello, who is married to Navarra’s mother, initially told the authorities on Sept. 8 he had stopped by the victim’s house for 15 minutes when he brought her a pizza. A little while after he had left her residency, Aiello claimed he spotted his stepdaughter drive off with someone else in the passenger seat of a car, ABC News reported.

However, on both accounts, Aiello’s account of the events faltered. After analyzing the surveillance footage, the investigators found Aiello’s car was parked outside Navarra’s house for at least 21 minutes on the day of her death, from 3:12 p.m. (6:12 p.m. EDT) to at least 3:33 p.m. (6:33 p.m. EDT) which meant he was present at her house during the victim’s death. The same footage determined the victim never drove that day.

“After explaining the abilities of the Fitbit to record time, physical movement and heart rate data, he was informed that the victim was deceased prior to his leaving the house,” the document read. “Aiello stated that could not be true because she had walked him to the door when he left the residence.”

Although Aiello mentioned earlier he did not see anyone else in Navarro’s house when he left, he began insisting “someone else might have been in the house," once he was informed of what the Fitbit data meant.

The San Jose police also found two shirts with blood stains on them in his garage, which according to Aiello got there as a result of him having cut himself.

"He was told that the deposits of blood were not localized in one area and were more consistent with splatter," the document said. "Aiello indicated that he might have cut his hand and shaken it while he was wearing those shirts."

Aiello was remanded in police custody without bail.