CENTENNIAL, Colo. -- The youngest surviving child living with Aaron Thompson testified against him on Tuesday, but because a therapist worried about the "trauma" she might have seeing Thompson face-to-face, the girl was in another room, on closed-circuit TV.

The 13-year-old told the jury it was usually "Big Aaron" who would give the "whoopin's."

A social worker had testified earlier that the girl had developmental issues, but the judge, Valeria Spencer, had found the child to be a competent witness before trial began.

Thompson is currently on trial, facing 60 charges, including numerous counts of child abuse. He is also accused of child abuse resulting in the death of his daughter, Aarone Thompson, whom he had reported missing. Thompson's live-in girlfriend, Shely Lowe, died before she was arrested. She was the mother of five of the children living in the house and the sister to one of the other children in the house.

On the stand, the girl who testified Tuesday sounded far younger than her 13 years. She seemed more of a preschooler than a teen.

She arrived in the other courtroom smiling, wearing ponytails adorned with blue ribbons, a black short-sleeved T-shirt and a multi-colored, checked dress.

Because of concerns she might be intimidated by the presence of Thompson, she was allowed to testify by closed-circuit television. With two cameras and two screens for the jury, the witness was easily seen and heard, even from the back of the room.

Prosecutor Amy Richards took her through a very brief, 5- to 7-minute's worth of direct examination.

Richards: "Where did you go when you got in trouble?"
Witness: "Downstairs in (the) basement ... whooped."
Richards: "What were you whooped with?"
Witness: "Belt."
Richards: "Where were you whooped with the belt?"
Witness: "(On) my butt."
Richards: "How often? Was this one time?"
Witness: "More than one time."
Richards: "Who was giving you the whoopin'?"
Witness: "Big Aaron."
Richards: "Not Shely (Lowe)?"
Witness: "Nope." Richards: "What else happened when you got in trouble?"
Witness: "Beat me.
Richards: "Who?"
Witness: "Shely"
Richards: "With what?"
Witness: "A bat."

Last week, the jury held a full-size wooden baseball bat and a man's belt taken from the Aurora home in their hands. On Monday, they saw a picture of the basement and a wooden pole extending from ceiling to floor.

Another girl in the home testified Monday that that's the pole used for especially violent "whoopin's." She explained that a child would extend his or her arms around the pole, another child would tie their wrists together using one of Lowe's scarves, while Thompson administered the punishment.

On Tuesday, the 13-year-old girl said that she saw other kids in the home beaten, including one punched in the eye by Lowe and another punched in the face by Thompson.

She was asked to look at pictures of all the seven kids who had lived with her and quickly named all of them, including "little Aarone." Her voice had changed slightly when she saw the picture of her missing and presumed dead bunkmate.

Richards: "What do you remember about her?"
Witness: "Played with me."
Richards: "What did you two do to play?"
Witness: "Jump on the bed."
Richards: "Which bed?"
Witness: "Every bed."

At this, the tension was broken by slight giggles from the jury and court observers.

The girl would later say she played basketball outside with the "smaller" Aarone but never saw her "sister" get in trouble. Later, under a cross examination of less than three minutes, the child got confused about where the "whoopin's" happened and was excused.

Thompson reported Aarone missing on Nov. 14, 2005, but police presumed she is dead and had been dead for year. Her body has never been found.

But as the case moves toward the child abuse allegations against Thompson, the children are stepping forward to make their allegations live and in person.

On Monday, a 14-year-old girl, named TL, was very composed and calm in her recounting of beatings by several methods, including belt, bat and coaxial cable.

A social worker, Andrea Woods with the Arapahoe County Department of Human Services, talked about finding health problems with some of the kids after were removed from the Thompson home in 2005.

The youngest child was "developmentally delayed," Woods said.

Case workers ensured the youngest child had her adnoids and tonsils removed to deal with "Darth Vader"-style heavy breathing. She also had hip surgery and Woods said the girl now walks much easier.

Another child, a boy, had a problem with encopresis -- soiling oneself before getting to the bathroom, Woods said.

Woods said she asked Lowe about that and was told, "they had it under control. That he had it for three years and went to the doctor." Once placed in foster care, the boy was taken to Children's Hospital and "still has difficulties" with the condition, Woods said.

Police found plastic grocery store bags with soiled pairs of boy's underwear in the East Kepner Place home during extensive searches in November 2005.

TheDenverChannel is not identifying the children at all in this section due to descriptions of personal medical conditions.