A Fort Bliss soldier and his wife were arrested Tuesday on charges of killing a 2-year-old girl in their care and seriously injuring her older brother while their military parents served overseas.

Investigators were working with the military to reach the children's parents - their father is stationed in Iraq and their mother in Germany.

Staff Sgt. Nakia Dawkins, 32, and his 29-year-old wife, Shawntrell Dawkins, were booked into the El Paso County jail on charges of capital murder and abuse of a child.

Police described them as the children's guardians and not blood relatives. El Paso police Officer Chris Mears said he didn't know the couple's exact relationship to the children's parents.

Both suspects are being held without bail. Jail and court records do not show if either has hired a lawyer.

Mears said officers went to the couple's apartment about 10 p.m. Monday after receiving a call that the 2-year-old was not breathing. They found the girl and her 4-year-old brother with "visible injuries," Mears said.

According to a pair of complaint affidavits filed in the case, the Dawkinses initially told investigators that the girl was injured after falling down several stairs in the couple's apartment.

The boy suffered similar injuries, which police concluded were "not consistent with the reported fall," the affidavits show.

Both children were taken to a local hospital, where the girl was pronounced dead. Records show that she suffered "numerous blunt force trauma injuries."

The boy was being treated for his injuries, Mears said.

According to the affidavits, both suspects told police they injured the children.

Mears declined to name the children or their parents, citing privacy issues concerning the boy. He said the boy is likely to be placed in state custody until his parents or other relatives can be located.

Army officials at Fort Bliss said Tuesday they did not have any details of Nakia Dawkins' service or his unit.