The defense attorney representing a Houston mother who is accused of drowning and decapitating her 5-year-old son described the woman as a “very mentally ill individual” after she appeared in court on Friday.

His client, Lihui Liu, has been charged with capital murder and held without bond in the death of her son, Jiandong Xu. The boy was found headless and stashed in a trash can at their home on Nov. 30.

Attorney George Parnham, who is known for representing Andrea Yates and Clara Harris in their high-profile murder cases, said Liu is receiving mental health help in jail and is taking medication.

“My observations support a very mentally ill individual,” Parnham said. “Just a sad situation all the way around.”

Speaking quietly and through a Mandarin translator, Liu stood before Judge Susan Brown, of the 185th Criminal Court, on Friday to hear her legal warnings.

After the procedural court hearing, Harris County prosecutors emphasized the nature of the crime and urged the public to think of the boy’s family at this time.

“This is a horrific, tragic, tragic, case,” said Michele Oncken, division chief of the Harris County District Attorney’s Office’s child fatality division. “What we want everyone to just have their minds and their hearts just thinking about, the family, this little boy, a 5-year-old child who was murdered and taken from this world much, much too soon. It is really unthinkable.”

The 43-year-old mother was arrested one week ago after Houston police responded to a stabbing call around 7 p.m. at the family's home in the 13000 block of Holly Lynn.

After the father came home to find the bloody scene, officers arrived and saw the slain child on the garage floor, headless and partially covered by a plastic bag.

The father told police that he’d left his wife home that morning with their 5-year-old son and 13-year-old daughter. His wife was in the garage when he returned, saying she’d sent the boy away.

While his father was looking for the boy, Liu said the child was in the trash can, police said. The body was wrapped in a black plastic bag, and the severed head was found in the same bin.

Police also found a bloody knife in the bathroom and a blood-spattered bathtub. During questioning, Liu allegedly admitted to drowning the boy but wouldn’t talk about the decapitation.

Liu doesn’t appear to have any prior criminal history in Harris County. Her husband, Kai Xu, told the Houston Chronicle that his wife had been experiencing a downward spiral with depression, starting in March. She was being treated for mental health problems after a suicide attempt in August, he said, about a year after she underwent a hysterectomy to remove a mass.

Xu was present at the court hearing Friday but declined to speak with the media.

Child Protective Services confirmed they'd interacted with the family back in 2015, though the children were never in state custody. It's not clear why CPS was involved with the west Houston family to begin with, or how that involvement ended.

The 13-year-old daughter is staying with the father, CPS confirmed on Friday.

Parnham said that Liu, who is from Singapore, is in a state of not being able to communicate. Whether that’s from not being able to understand his questions or not being able to process an answer is unclear, he said.

“Of course, there’s a great deal of grief involved,” Parnham said. “The very facts of the situation speak to an action of irrational mind.”

Prosecutors have requested that the judge officially approve no bond in Liu’s case. A judge in Harris County Probable Cause Court set no bond last week.

Prosecutors will meet on a committee and determine whether they will pursue that the death penalty, Oncken said. If they don’t and Liu is found guilty, she would automatically be sentenced to life without parole.

samantha.ketterer@chron.com

Twitter.com/sam_kett