Corey Howard, 3, died later that night from smoke inhalation and complications from the heat of the fire. His older brother Mason, 4, died Nov. 17, and Corey's twin sister, Brandi, died Nov. 18.
The fire has been ruled an arson, Games-Neely said.
Martinsburg Police Chief Ted Anderson, Detective Sgt. George Swartwood, Games-Neely and other investigators met for almost an hour at her office on Tuesday afternoon. The group got a last bit of information from the federal Bureau of Alcohol, Tobacco and Firearms on Tuesday, leading to the decision to rule the fire an arson. Approximately 15 people were involved in the investigation.
The fire at the two-story gray house began in an upholstered chair in the living room on the first floor, Games-Neely said.
While there was smoke, there were no observable flames in the house until after firefighters arrived, Games-Neely said.
No accelerant has been found, Games-Neely said. Fire investigators ruled out an electrical fire or spontaneous combustion, she said.
Games-Neely said investigators weren't able to gather enough evidence to pursue an arson charge even though every test available was conducted and an ATF fire projection engineer assisted.
A child neglect charge alleges a parent unreasonably failed to "exercise a minimum degree of care" to assure the child's safety and health, Games-Neely said.
A conviction on a charge of felony child neglect resulting in death is punishable by three to 15 years in jail and/or a fine of $1,000 to $5,000, Games-Neely said.
Howard has been staying with relatives in nearby Pennsylvania and will be extradited if she does not voluntarily return to West Virginia, Games-Neely said.
Games-Neely said Howard returned to Martinsburg for an interview with Martinsburg City Police investigators.
During their last evening together, the children ate macaroni and cheese for dinner and watched television, Games-Neely said.
Later they went to bed, Mason Howard sleeping alone in a room down the hall from the twins, Games-Neely said. She said Howard's husband, Michael Howard, was at work and her teenage daughter was not home.
Games-Neely and fire officials said Howard, uninjured, climbed out the window in the twins' bedroom and yelled for someone to help her children.
Howard was wearing a nightgown, robe and glasses and had a pillow or pillowcase with her to protect her face from smoke, Games-Neely said.
A smoke detector on the second floor of the house, where the children's bedrooms were, contained no batteries, Martinsburg Fire Capt. David Brining has said.
There were no major life insurance policies on the children, and the house was rented, Games-Neely said. Investigators did not find any sign of a break-in, she said.
In an unrelated matter, Howard was charged June 1, 1999, with child neglect after Brandi Howard, then 2, was found near the street, dirty and wearing only a diaper, in the 800 block of Winchester Avenue around 9 a.m., court records alleged. At that time, the family lived at 735 Winchester Ave.
The child had been without supervision for at least 30 minutes, police alleged in court records.