Joseph L. Smith, 32, was arrested Sunday morning following the standoff at an Atlanta apartment complex where he lived, The Atlanta Journal-Constitution reported.
East Point, Ga., police spokesman Cliff Chandler said Smith is suspected of killing a woman, identified as Loveitt Wallace, 36, who was found dead in an East Point hotel room.
Smith is also suspected of killing his newlywed wife, Shatikey Griffin, 34, and her daughter, who were found in the apartment the standoff took place in, the newspaper said.
"He turned himself over to police during the negotiations," Atlanta police Lt. Paul Guerrucci said Sunday afternoon. "We are speaking with him right now."
Griffin's father, Thaddues Griffin, told the Journal-Constitution that his daughter and Smith had only been married for about a month. He also identified his deceased granddaughter as 12-year-old Demiya Griffin, who was a student at Kipp Ways Academy.
"This is a tragic loss to the KIPP WAYS Academy Team & Family," Kipp Ways Academy Principal Dwight Ho-Sang said in a statement released Sunday night. "Demiya was an incredibly sweet young girl who consistently demonstrated the school's values and was a great teammate. As an honor roll student who loved theater, Demiya had a very bright future ahead of her. We will miss her warm smile and bubbly personality."