(CNN) -- Two children, who were the subject of an Amber Alert, have been found safe -- and authorities say they are key to an investigation into the death of two people in a south-central Kentucky home.
"They were found safe," said Kentucky State Trooper Billy Gregory late Tuesday night.
A firefighter spotted 15-year-old Christopher Endicott and 12-year-old Kyra Shockley while they were driving a missing 1997 white Chevrolet Lumina on a highway in Barren County, Gregory said.
The Amber Alert was issued after Gary and Barbara Holloway were found dead in a Metcalfe County home and the children could not be found.
Asked if the children are possible suspects in the deaths of the Holloways, Gregory said authorities are considering "every possible scenario."
"We can't ignore the possibility," he said. "I think they are the key to the investigation."
The Holloways were married and became legal guardians of Endicott earlier this year, according to Gregory. The teen lived at their home.