Davis Officer Kimberly Walker’s voice faltered with emotion as she recalled seeing young Tatiana Garcia for the last time, carried on her mother’s hip, when shouts broke the courtroom’s quiet.

“You let me down! You let me down!” Aquelin Talamantes shouted at the witness stand, blaming the police officer who checked on her at her Davis home on Sept. 26, 2013, for not doing more in the hours before prosecutors say Talamantes drowned her 5-year-old daughter.

The afternoon outburst was one of several emotionally charged moments in a dramatic first day of testimony Tuesday at Talamantes’ murder trial in Yolo Superior Court in Woodland. Talamantes, 29, faces charges of murder, as well as assault on a child younger than 8 years that resulted in death. She has pleaded not guilty to the charges. The Davis woman is accused of drowning Tatiana in the bathtub of the home where Talamantes and her two children lived with her sister.

Walker and other officers, struck by Talamantes’ odd behavior in the hours before Tatiana’s death, had walked through the home on a welfare check, Walker testified. Hours later, Tatiana was found by police in the trunk of Talamantes’ car in the parking lot of her sister Priscilla Talamantes’ Sacramento apartment complex.

Yolo County jurors watched the dramatic split-screen video from a police dash-cam as opening statements began Tuesday. Wearing Hello Kitty pajamas, Tatiana was wrapped in a Mickey Mouse blanket and covered with a plastic bag in the trunk of her mother’s car when officers found her and began CPR in a frantic attempt to save her life. In the back seat of a patrol car, her mother was under arrest on suspicion of killing her daughter.

“Come on, baby! Come on, baby!” the officer pleaded as he pumped the 5-year-old’s chest. Sobs could be heard in the background.

Prosecutors say Talamantes pulled her daughter from the bathtub, stowed her in the trunk of her Honda sedan and drove to another sister’s home in Sacramento’s Pocket neighborhood, where police and family members made the grim discovery.

“This is Aquelin Talamantes,” Yolo County Deputy District Attorney Ryan Couzens told the jury in Woodland. “She was the mother of a beautiful girl until she pushed her under water for 15 seconds,” Couzens said. “For a child, an eternity.”

In Couzens’ opening statement, he portrayed a woman addicted to numerous drugs and painkillers who resented her children for quashing her dreams of songwriting, modeling and dancing.

Couzens played a recording of Talamantes venting her frustration in an interview with police.

“Stupid kids. I can’t take care of them. I don’t want them,” she was heard saying.

Walker’s testimony of the hours before the girl’s death dominated the Tuesday afternoon session. Walker described a restless, unfocused Talamantes, who told her she was a paranoid schizophrenic who battled depression and bounced with her children to and from relatives’ homes. Her latest stop was the Glide Avenue home of sister Elisa Torres – a matriarch of sorts since the violent death of their mother years earlier.

Talamantes “looked concerned and lost – it struck me as quite curious,” Walker said. Talamantes talked of her mental health visits, including a late-night drive earlier that year to a Sutter Health mental health facility in Sacramento and the whispers she heard in her head, Walker testified.

Talamantes had struggled with mental illness for years, Yolo County Deputy Public Defender Sally Fredericksen said earlier in the day, stemming from repeated sexual abuse as a child and the violent death of her mother when Talamantes was 11 years old. Fredericksen said a violent six-year relationship with the father of her two children further deteriorated her mental state.

On the stand, Walker said the walk-through quickly morphed into a psychiatric evaluation – called a “5150 evaluation,” after the Health and Welfare Code section – to determine whether Talamantes could care for herself and children, and if she had thoughts of harming herself or others.

Torres said she was working to gain custody of the children, so unsure was she of Talamantes’ fitness to raise them, Walker testified, adding that Torres said she became the primary caretaker when Talamantes took prescription medications to regulate her mood.

Still, Walker testified, she “didn’t have anything” on which to admit Talamantes into mental health care. “She just did not meet the criteria,” Walker said.

That afternoon, Torres returned to the Glide Avenue home to find Talamantes and her 4-year-old son, but no sign of Tatiana.

“Where’s Tatiana?” Walker said Torres asked. “Where’s Tatiana?”

Talamantes asked in response, “Are you going to get me in trouble?”

A few minutes later, Torres heard the sound of her sister’s car leaving Glide Avenue.