The boy charged with murdering family members 18 months ago on retired ABC newsman Sam Donaldson's Lincoln County ranch finished his testimony on Friday.

Cody Posey, 16, has admitted to shooting his father, Delbert Paul Posey, Donaldson's ranch manager; his stepmother, Tryone Posey; and Marilea Schmid, 13, his stepsister. All were shot in the head; however, a lawyer was not present when Posey confessed two days later. He was 14 at the time.

"What were your family's rules (regarding school)," Mitchell asked during Friday's testimony.

"The rule was I was to go to school, do my work and come home. The rule was school wasn't a social place," Posey said.

"How would your family find out (what you did) at school?" Mitchell asked.

"A lot of times (Marilea) went home and told them. It upset me because a lot of times things were being said about me that weren't true. I would go home and be asked several questions and if I didn't know about it I would (be accused of) lying," Posey said.

In the courtroom, former Cloudcroft classmates listened as Posey described the punishments.

"What was the family ritual whenever you were punished?" Mitchell asked.

"It was kind of a tag-team deal. My father would come in and start yelling and screaming, hitting me. After he was done it would seem like Tryone would come in and start hitting me. After they were done Marilea would come in and have some things to say about the situation," Posey said.

When he was bruised he said he "was told to lie" about his injuries.

"He (my father) said if I did turn him in ... when he gets out of jail he would come hunt for me and get back at me for what I did to him," Posey said.

On July 4, the night before the shootings, Posey said his dad tried to force him into sex with his stepmother. That, he said, created a whirlwind of emotions and he asked himself "why my life had been like this; why that night had happened."

He was in his room when his parents summoned him.

"As I entered the room my dad was standing to the left of the bed with Tryone laying on the bed at the head of the bed. She was laying there covered up at the time," Posey testified.

His dad was heating a metal rod with a butane tank, he said.

"My dad stoked up the torch and told me I was going to have sex with Tryone. I refused to do it," he said. "He walked up to me and burned me."

Mitchell has entered into evidence photographs of those marks.

"As he burned me he told me to do it, again. I said no," Posey testified. "Tryone pulled down the covers and she was laying there completely naked. ... I remember Tryone scooting down to the foot of the bed. She grabbed my head and put it between her breasts. ... I believe she was telling me something, being that we're not family it was an OK thing to do."

Posey said he bit his stepmother to escape her grasp.

"I felt very disgusting, I felt dirty, I felt like -- I just felt like I was lying and rolling in the dirt," Posey said.

The next morning he rose and tackled chores. Posey said his father acted as if nothing was unusual, the two got into an argument and Delbert Posey backhanded his son.

Posey did not describe the shootings later that day other than to say, "I lost control. I didn't know what I was thinking. I didn't know what I was doing. ... I myself wish I knew what I was thinking. I more or less lost my mind, sir."

Senior Trial Prosecutor Sandra Grisham stated Posey knew exactly what he was thinking. She introduced a letter Posey had written in summer 2004 to the parents of a girlfriend in Capitan. Posey wrote he was a "screw-up," and admitted lying, stealing, cheating, disobeying, and indulging in "illegal drugs."

On the stand, he also admitted smoking marijuana at Hondo school. Grisham suggested Delbert Posey pulled his son from Hondo schools to get him away from drugs. Posey said he took acid when he was 10 and living with his mother before she died, after he found the drug in a drawer but didn't know what it was.

Grisham had Posey read a 2,000-word essay his father told him write "on why I messed up," Posey said. In it, he wrote such sentences as: "I've never changed before because I didn't want to change"; "I watch all my friends and the way they act and when I (act like them) I get into trouble"; "I want to fit in and not be an outcast so I do what I see and not what I'm told"; and, "I was back-talking you because I thought I was better and smarter."

Posey testified the essay wasn't wholly truthful.

"The whole tone of this letter, who's it for?" Mitchell asked.

"My father," Posey said. "There have been times where I have messed up in my childhood, but in the whole paper it talks about all I do is mess up -- and that's not true."

Grisham countered Posey's family life was not the Dickensian hell he depicted. She introduced a poem Marilea wrote that included the phrase: "We laugh the night away 'til each wanders to his room."

"So at least in Marilea's mind life was not an unrelenting torture day after day after day," Grisham said.

Grisham also questioned Posey on video games he played such as "Tom Clancy's Shadow Ops," and "Grand Theft Auto."

"That involved shooting cops, doesn't it?" she asked.

"In certain parts of the game, yes," Posey said.

"You get extra points for headshots, don't you?" Grisham said.

Mitchell objected and she withdrew the question.

"Finally, Cody, your dad bragged about what a good shot you were, didn't he?" Grisham said.

Posey's face fell. Mitchell objected, but Judge James Waylon Counts allowed the question.

"Yes ma'am, I've been known to shoot well," Posey said.

Testimony concluded with two ranch hands Posey worked with. Isabel Vasquez, speaking through an interpreter, said Delbert frequently derided his son with "bad words."

He described Delbert hitting his son on the hands with leather reins while riding a horse when Cody dropped his own reins and held onto the saddle horn.

"He wasn't doing anything wrong. I was doing that (putting my hands on the saddle horn) and there wasn't anything wrong with it," Vasquez said. "I thought in my eyes it wasn't right."

Vasquez said on occasion Delbert withheld food from Cody -- once even water on a hot day -- even when he, Vasquez, offered Cody some of his lunch. Vasquez said he saw Delbert grab at Cody when the boy wouldn't call him "sir," and hit him so hard -- including with a rock -- that Cody's "tears started running."

Vasquez testified that when Cody repeatedly popped the clutch on a pickup truck, Delbert took a curved hay hook and thrust it into the boy's crotch.

"'The next time you do that with the truck, with the (hay hook) I'm going to' -- and excuse my word, I'm going to say balls -- 'with the same (hay hook) I'm going to cut them,'" Vasquez said. "I saw it because I was by his side."

According to Vasquez, Delbert once told him "he did not want to have another child like Cody." He testified Tryone said when Cody was graduated from high school the boy would no longer be welcome in the house.

Conversely, he said, the Poseys treated Marilea like "the queen of the house."

"He was a good kid," said former ranch hand Clint Skeen, 18. "When Cody was around me I could tell he was happy. When Paul entered the picture I could tell he was like a whipped dog. ... I saw some verbal abuse where Paul screamed at him, called him some pretty terrible names (that are unprintable)."

He said Tryone treated Posey the same, once blowing up at Posey when the boy simply got food from the refrigerator.

"He was expected (to do) a lot more for the age that he was at," Skeen said.