A second suspect in the deadly shooting of a Powder Springs couple is in police custody.

Powder Springs Police Chief John Robison spoke with WSB Radio on Friday following the arrest of the suspect who he has identified as DeMarco Thomas.

Robison says it is possible that drugs were involved when Anthony and Catherine Costner met with Thomas and another suspect, Roy Hicks, on Aug. 6.

Hicks, who is from Smyrna, was arrested two days after the shooting.

Police suspect Hicks fatally shot the couple. Robison said that Hicks is recovering from a gunshot wound, which is believed to have occurred during the shooting.

The couple was found in their car in a ditch near 3790 Parks Drive. Their three-year-old daughter was found unharmed in the back seat of the car.
 
Anthony, 24, was pronounced dead at the scene and Catherine, 22, later died at the hospital.

Cynthia Quinn, Catherine's mother, told WSB that she wondered who would shoot a mother and father in front of their child.
 
"I think someone had it in for her husband for some reason," she added.
 
Family members said the couple had left home to go help someone when they were killed.
 
Police say the investigation is still very active.