TACOMA, Wash. -- A 22-year-old female Fort Lewis soldier is under investigation in the killing of two other soldiers and the abduction of the couple's 7-month-old daughter.

Deputies said the 22-year-old soldier was booked into the Pierce County Jail in Tacoma on suspicion of two counts of first-degree murder and one count of kidnapping.

Pierce County Sheriff's Office representative Ed Troyer said deputies acting on information from the U.S. Army, went to a home in the county Sunday and found two people, a man and a woman, dead. The couple were medics at Madigan Army Medical Center at Fort Lewis and members of the fort's honor guard.

"We're working with the military police to determine what led up to this and what the relationship was before the homicide. At this point we just don't know that," Troyer said.

The victims are believed to be in their early to mid-20s and appeared to have died from gunshot wounds, thought to have been inflicted on Saturday. They have not been identified.

The infant girl belonging to the couple was missing from the home and was found with the Fort Lewis soldier. The baby was not harmed and is in the care of the state's Child Protective Services agency.