SEATTLE – The Army has taken over the prosecution of a Fort Lewis chemical operations specialist accused of killing two other soldiers – a married couple – and pouring acid on their bodies.

Spc. Ivette Davila, 22, was transferred from the Pierce County Jail to the Navy’s brig at its submarine base at Bangor. The Army’s confinement facility at Fort Lewis is being renovated.

The Army plans to announce charges by the end of the week, Fort Lewis spokesman Joe Piek said Wednesday.

Davila, originally from Bakersfield, Calif., is accused of shooting and killing Sgt. Timothy Miller, 27, and his wife, Sgt. Randi Miller, 25, at their home near Tacoma on Saturday night.

A declaration filed in Pierce County Superior Court on Monday by Deputy Prosecutor Ed Murphy says Davila took the couple’s 6-month-old daughter to a home-improvement store and bought muriatic acid, which she poured on the bodies to dispose of them, the declaration said.

The next day Davila confessed what she had done to a fellow soldier, according to the document, and she claimed Randi Miller had a relationship with her ex-boyfriend. The infant was not harmed and by Wednesday was in the custody of Timothy Miller’s family.

Timothy Miller served in Iraq and South Korea during a 10-year military career. Originally from Gardnerville, Nev., he was posthumously promoted to staff sergeant. Randi Miller, originally from Lowell, Mass., served in Iraq from March to November 2006 with the 47th Combat Support Hospital. The unit spent much of that year in northern Iraq.

Davila underwent basic training and chemical operations training at Fort Leonard Wood, Mo., before reporting to Fort Lewis in June 2005.