A mother suspected of killing her month-old daughter in 2005 by putting her in a microwave oven was indicted Thursday on a charge of aggravated murder, and the prosecutor said he would seek the death penalty.

The indictment against China Arnold, 26, does not provide details on the death of Paris Talley. Investigators have said evidence that includes high-heat internal injuries and the absence of external burn marks on the baby were consistent with a microwave oven.

"The Montgomery County coroner came to the conclusion that the injuries sustained by this baby could have only been caused by being placed into a microwave oven and having that oven turned on and cooked the baby to death," Montgomery Country Prosecutor Mathias Heck Jr. said at a news conference.

Heck said Arnold would be subject to the death penalty if convicted because the victim was a child.

Heck said the baby was killed in the early morning hours of Aug. 30, 2005, at Arnold's home. He declined to discuss motive or release any other details about the case.

Arnold took the baby to the hospital after finding her unconscious at home, according to defense attorney Jon Paul Rion. He said she told hospital officials she did not know what had happened to the child.

Rion has said Arnold had nothing to do with her daughter's death and was stunned when she was told a microwave might have been involved. He said she plans to plead not guilty.

"China has the moral courage and the confidence in her God that the truth will come out in this case," Rion said. "We will seek every single way possible to communicate to our government and to the jury in this case that China is innocent of all the charges."

Police said a microwave oven was taken as evidence. Ken Betz, director of the Montgomery County coroner's office, said the case was difficult because there is not a lot of scientific research on the effect of microwaves on humans.

The night before the baby was taken to the hospital, Arnold and the child's father went out for a short time and left the child with a baby sitter, Rion said. The mother didn't sense anything out of the ordinary until the next morning, when the child was found unconscious, Rion said.

Arnold was arrested Nov. 27. She is being held on $1 million bond in the Montgomery County Jail.

Heck said he will ask the court to order Arnold held without bond. She is scheduled to be arraigned Tuesday.