Updated

The human remains found at the scene of the Christmas Eve shootings of four upstate New York firefighters have been identified as the gunman's sister.

The sheriff in Monroe County, where Rochester is located, tells local media that a medical examiner made the identification of the remains of 67-year-old Cheryl Spengler. Authorities say she died from a gunshot wound to the head. Her death was ruled a homicide.

Her remains were found in the charred debris of William Spengler's lakeside home in the suburban town of Webster. Authorities say the 62-year-old Spengler set fire to his home, then ambushed volunteer firefighters who arrived to put out the blaze. Two firefighters were shot to death and two others were wounded.

Spengler committed suicide after a shootout with a police officer.