"He was waiting on us when we got here, and we took him into custody without incident," Pierce said.
Inside the home, investigators found the body of 58-year-old Diane McElrath.
Other family members, including two men who identified themselves as the suspect's brothers, arrived at the home shortly after the officers and were assisting investigators, Pierce said. Damian and Diane McElrath were believed to be the only people in the home at the time of the stabbing.
Investigators had been dispatched to the home previously, but Pierce declined to release information regarding those incidents.
Police released the names of those involved late Monday, following notification of other family members. Investigators remained at the scene Monday evening, when the victim's body was removed from the home by a county medical examiner.
Shortly after 7 p.m., Damian McElrath was arrested and charged with murder and aggravated assault and booked into Cobb County jail, online records showed. The 18-year-old's arrest came less than two months after he was released from the jail in another case, booking records showed. On Tuesday, McElrath was also charged with violating probation, according to jail records.
Damian McElrath had been arrested May 2 for violating his probation following a conviction for a December arrest.
On Dec. 2, McElrath broke the glass in a display case and took four iPads from a Target store on Dallas Highway before being apprehended in the store's parking lot, according to an arrest warrant obtained by the AJC. He also threatened to kill the Cobb County officer attempting to arrest him, the warrant stated.
In November 2010, Damian McElrath was charged with drug possession and fighting in a public place following an arrest at an alternative school, according to the arrest warrant.
He remained in jail without bond Tuesday evening.