The lone survivor of the attack, the couple's 15-year-old daughter, was in critical condition in a Houston hospital.
Haskell had a handful of previous run-ins with law enforcement in Utah, where he had lived with his now-ex-wife in Logan and Smithfield. 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.
Utah court records show that Haskell's divorce, initiated in August 2013 by Melanie Kaye Haskell, was finalized on Feb. 14. A month before filing for divorce, the woman obtained a protective order against Ronald Haskell.
The divorce case shows Ronald Haskell was living in Cache County at least as of December 2013.
Utah law enforcement officials said in a Thursday release that Ronald Haskell has had several involvements with the Logan City Police Department. He was booked into the Cache County jail in June 2008 after Melanie Haskell reported he had hit her in the head and dragged her by the hair, according to police and court records.
It was not immediately clear why Haskell showed up in the Houston suburb of Spring on Wednesday, demanding to know where he could find his wife.
"She 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.
"I hadn't heard anything about (Haskell) at all for a long time, for him to show up here," she added.
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."
"I don't think any of us will ever be able to see that house the same again," said Viri Palacios, who lives across the street. "I just want the word to get out they were a really, really good family."
A few blocks from the home at Lemm Elementary School, Principal Kathy Brown tied multi-colored ribbons around trees in front of the building and encouraged parents to do the same.
"It's to have positive bright thoughts about the family," Brown said, noting that two of the slain children had attended school there and a third had graduated from Lemm.
Documents introduced during a preliminary court hearing Thursday show the 15-year-old girl attempted to close the door to the home after telling Haskell her parents were not home, according to a report by Houston television station KPRC. But he kicked in the door.
Harris County Constable Ron Hickman said Haskell showed up at the Stay home "in the guise of a FedEx driver wearing a FedEx shirt."
Haskell had once done work for FedEx but not since January, the company said in a statement.
After Haskell left the home, the badly wounded teenage girl contacted authorities, telling them the gunman was planning to shoot other family members, Hickman said.
Police located Haskell's car and a low-speed chase ensued, ending in a cul-de-sac, Hickman said. A standoff lasted more than three hours before Haskell exited the car, sank to his knees and surrendered.
Online jail records did not list an attorney for Haskell.
His divorce decree issued in February shows that 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.
At the time of the divorce, Haskell was making $2,300 a month, although the records do not say what kind of work he did. He was ordered to pay $773 per month in child support. His wife was given the house, valued at $190,000, in the small town of Smithfield, Utah, just outside Logan.
Associated Press writers Emily Schmall in Fort Worth, David Warren in Dallas and Brady McCombs in Salt Lake City contributed to this report.