The 26-year-old Milton-Freewater mother facing charges of murdering her child deferred entering a plea during an arraignment Monday afternoon.

Milton-Freewater police arrested Loretta Maxine Polanco on Sunday on the suspicion she murdered her two-year old boy, Lucas Isaac Polanco. The office of Umatilla County District Attorney Dean Gushwa filed a murder by abuse charge against the mother, as well as charges of murder, manslaughter, first-degree assault and first-degree criminal mistreatment. All are felony charges.

Gushwa said he plans to present evidence in the case to a grand jury this week.

Polanco appeared Monday afternoon before Circuit Court Judge Christopher Brauer via a closed circuit TV monitor from the Umatilla County Jail in Pendleton. Polanco deferred entering a plea, and the court scheduled a preliminary hearing for Polanco at 1:15 p.m. Monday in Courtroom No. 1 at the Umatilla County Courthouse in Pendleton. Polanco will likely enter a plea then.

The case began Saturday, according to a news release from Gushwa’s office, after paramedics responded to a Milton-Freewater residence about a 2-year-old child who wasn’t breathing or moving. An ambulance took the boy to St. Mary Medical Center in Walla Walla, and from there a helicopter ambulance flew him to Doernbecher Children’s Hospital in Portland.

Milton-Freewater Police Chief Doug Boedigheimer referred questions about the case to Gushwa.

Gushwa said the child suffered from head and liver trauma and possibly other injuries. He said the alleged abuse may have occurred over a six-month period. Gushwa said doctors disconnected life support devices Sunday from the child, who then died.

Polanco went with the boy on the flight. Milton-Freewater police officers followed her to Portland, arrested her at the hospital around 5 p.m. Sunday and took her to the Umatilla County Jail in Pendleton, where she has been since early Monday morning.

Police questioned Polanco, Gushwa said, and that resulted in the arrest. Police also searched Polanco’s home at 411 N.W. Second St., Milton-Freewater.

Gushwa said the Oregon State Police crime lab is investigating forensic evidence in this case, which remains an active investigation.

Polanco has past convictions for possession of methamphetamine, first- and second-degree theft and second-degree forgery. Judges have usually given Polanco probation for her crimes, although she served six months in jail after she pleaded guilty to possession of meth in January 2007. Court records do not show Polanco had a history of violent behavior.