ASTORIA, Ore. » Notes left by a mother accused of drowning her 2-year-old and cutting the throat of her teenage daughter recounted the attack and said the "baby didn’t suffer as she fell asleep in the water," according to an arrest warrant affidavit unsealed Tuesday.

The document was released as a Clatsop County Circuit Court judge accepted not guilty pleas from Jessica Smith to charges of aggravated murder and attempted aggravated murder. The murder charge could bring the death penalty if Smith is convicted.

Smith, 40, of Goldendale, Washington, appeared in court via video and smiled on several occasions during the 20-minute hearing. She nodded and winked when asked whether she understood that she would remain in jail at least until a Sept. 30 hearing.

Authorities have said Smith checked into the Surf Sand Resort in Cannon Beach on July 29 under her own name with her two daughters in tow. Three days later, a cleaning crew found the drowned body of the 2-year-old girl. The still-breathing teenager was covered in blood with her throat cut.

According to the affidavit, Smith gave her teenage daughter a double dose of a sleeping agent, then used a numbing compound on her neck before her throat was slashed.

Smith considered cutting the toddler’s throat, her 13-year-old daughter told an Oregon State Police detective, but chose to drown the child instead.

The state medical examiner, Dr. Karen Gunson, told The Oregonian that the 2-year-old had been heavily sedated with an over-the-counter antihistamine.

Gunson told the newspaper that asphyxiation by drowning was the main cause of the 2-year-old’s death and the drug was a "contributing cause."

The teen was identified in the affidavit but her name is being withheld by The Associated Press because of her age.

Prosecutors have declined to provide further details on the attacks.

In court Tuesday, Smith’s attorney William David Falls said the case is complex and he would need time to prepare for several possible defenses, including one based on Smith’s mental health.

Falls also said the publicity surrounding the case would make it more difficult to find an unbiased jury in Clatsop County.

On July 31, the children’s father, Greg Smith, told a Washington state detective that Jessica Smith sent his colleagues a 15-page email excoriating him and raising complaints about their marriage.

Greg and Jessica Smith’s surviving daughter told police the difficult relationship of her parents came up frequently in the motel room. The couple separated in April, and the teenage daughter told police Greg Smith was seeking custody of the children.