"His face, he obviously lost blood in his face, and his knees buckled," Haskell's attorney, Doug Durham, said. "He's scared. I think he has a limited mental capacity of what's going on."
Before the collapses, Haskell had acknowledged with a quiet "Yes" a couple of questions put to him by State District Judge Mark Kent Ellis about his legal rights. Ellis ordered Haskell held without bond.
Tammy Thomas, the lead Harris County assistant district attorney in the case, said she had no idea what was going on.
"Maybe reality is finally setting in," she said. "It's not television, this is not fiction. He is facing his consequences."
Thomas said she expected a grand jury to issue a capital murder indictment as a result of Wednesday's shooting that killed Stephen and Katie Stay along with four of their children, ranging in age from 4 to 14.
Authorities have said Haskell was searching for his ex-wife, Katie Stay's sister, when he forced his way into the home in the northern Houston suburb of Spring.
He tied up the family and put them face-down on the floor before shooting each in the back of the head, according to investigators. The family had refused to say where Haskell could find his ex-wife.
The lone survivor of the attack, the couple's 15-year-old daughter, suffered a fractured skull when a bullet grazed her head but was able to call 911 and provide Haskell's identity and description.
Durham, who has been appointed by the court as the defense counsel, said his focus will be Haskell's mental condition "and whether he was legally responsible at the time of his conduct."
"Obviously the evidence is very compelling that he was responsible for the deaths of these children and his ex-wife's sister and her husband," Durham said. "It's a terrible tragedy. The question is: Is he legally responsible from a criminal standpoint?"
He said state and national laws say a person suffering from severe mental illness is not criminally responsible if they can't distinguish right from wrong.
"And I think the evidence is going to show ... he is a troubled individual and he has a history of mental illness. Unfortunately, the delivery of the health care has failed in this system."
Thomas said the defense strategy was not surprising, "because there aren't many explanations otherwise for him to grasp."
But she said the probable cause in the case showed a "determined effort involved, the planning, the conscious decisions."
She said she would present evidence to a grand jury to seek a capital murder indictment and a decision on the death penalty would be made later by elected District Attorney Devon Anderson.
"It makes no difference to me whether he ever fully understands how much trouble he's in," Thomas said. "I'm going to let a jury tell him how much trouble he's in."
The San Diego County, California, sheriff's office said in a Thursday statement that Haskell's mother had reported an argument with her son July 2 at her home in San Marcos, California, during which Haskell physically restrained her when she tried to leave the house to call for help. Haskell finally left after a few hours, and his mother contacted 911, the statement says. She later obtained a restraining order against her son and the case remains under investigation, according to the statement.
Haskell also had a handful of previous run-ins with law enforcement in Utah, where he had lived with his wife. Neighbors said Haskell's marriage was so rocky that Stay went to Utah last fall to help her sister escape the relationship and start a new life in Texas.
Stay "was very instrumental in helping her sister get here so she could have a fresh start. Katie's a spitfire. She has energy to stand up for what she believes is right and true," said Verena Beckstrand, a neighbor who choked back tears as she talked about the family.
Documents presented at a preliminary court hearing for Haskell on Thursday say the daughter who survived the attack at the home in Spring attempted to close the door after telling Haskell her parents were not there, but he allegedly kicked it in. After the shootings, the teen played dead and called 911 when Haskell left the house, prosecutors said.
When the badly wounded daughter contacted authorities, she told them the gunman was planning to shoot other relatives, Harris County Constable Ron Hickman said. Police located Haskell's car and took him into custody after a three-hour standoff.
In a statement issued Thursday through the Harris County Sheriff's Office, Katie Stay's father, Roger Lyon, said his hospitalized granddaughter "is expected to make a full recovery."
"We are grateful for this miracle," Lyon said in his statement. "We are in awe of her bravery and courage in calling 911, an act that is likely to have saved all of our lives. She is our hero."
By Thursday morning, a small memorial with three candles and a plant had been set up at the front door of the family's two-story white-brick and brown wood-trimmed home. A couple with a child left a framed photo of the family with the inscription "Faith, Hope, Love."
The father, Stephen Stay, was a real estate broker. The mother was a helpful presence around the neighborhood, planning Halloween and Christmas parties for children, said Viri Palacios, who lives across the street.
"I don't think any of us will ever be able to see that house the same again," Palacios said. "I just want the word to get out they were a really, really good family."
Online jail records did not list an attorney for Haskell, who initially was misidentified by authorities as the slain children's father. Officials did not explain the mistake Thursday.
Haskell was wearing a FedEx shirt at the time of the attack, but authorities seemed uncertain whether it was a deliberate attempt to deceive. Hickman said investigators were not sure whether the suspect would have needed a disguise to get in the house, or if the children knew him.
Haskell had once done work for FedEx but not since January, the company said in a statement.
Haskell was previously jailed in 2008 in Logan, Utah, about 80 miles north of Salt Lake City, on charges of assault and domestic violence. His wife told police he dragged her by her hair and struck her in the head in front of their children.
Those charges were later dismissed as part of a plea deal, according to information released Thursday by Logan authorities.
Haskell also was served last year with a protective order from his ex-wife. It was dismissed in October after the couple filed for divorce, online court records show.
A divorce decree issued in February shows Haskell and Melanie Kaye Haskell were married in 2002 in Orange County, California. They separated in June 2013. A judge granted joint custody of the couple's four children, ranging in age from 3 to 11, with Haskell's wife getting primary custody.
Associated Press writers Emily Schmall in Fort Worth, David Warren in Dallas and Brady McCombs in Salt Lake City contributed to this report.
Plushnick-Masti can be followed on Twitter at https://twitter.com/RamitMastiAP .