SAN JOSE, Calif. (AP) — Authorities say a 91-year-old California man has died after he was arrested last year in the killing of his stepdaughter whose Fitbit helped provide clues to police.

The San Francisco Chronicle reports Tony Aiello died Tuesday at a hospital in San Jose where he was taken due to “deteriorating health” from pre-existing conditions.

Aiello was arrested last year in the death of 67-year-old Karen Navarra, who wore a device that tracked her steps and heart rate.

Authorities say Navarra’s Fitbit recorded a rapid rise in her heart rate before a sudden drop-off. Police say cameras captured Aiello’s car at Navarra’s home at the time her Fitbit showed her heartbeat rapidly falling.

An autopsy found “multiple deep and intrusive wounds” to her head and face, likely inflicted by a small hatchet or ax.

___

Information from: San Francisco Chronicle, http://www.sfgate.com