The victim, Sharon Sylvester Young, 45, was found dead inside a house in the Crystal Lake Country Club subdivision.
Police discovered her 3-year-old grandson alone in an unlocked vehicle while responding to an On-Star alert.
The discovery was made at about 12:52 p.m. Thursday in the 300 block of Masters Club Boulevard in Henry County.
An autopsy conducted by the Georgia Bureau of Investigation on Friday ruled the woman’s death a homicide.
Channel 2’s George Howell was at the scene as Henry County police searched the home for evidence.
“I don’t know if the child in particular knew that there was an emergency or maybe was just pushing buttons in the vehicle maybe,” said Sgt. Mike Ireland.
“I’m just really, really nervous about the whole situation,” said Laura Ervin, who lives in the neighborhood.
Neighbors said it’s difficult for strangers to enter or leave the neighborhood without passing by security.
“The security that we have here does an excellent job of making sure that people that come in that don’t live here actually go through the channels of calling the person, getting their OK, if they can come in,” said Dwayne White.
Police said that Preston Marzette Young may be driving a 2004 Maroon Dodge Ram bearing Georgia tag No. BKG 1602.