HOUSTON — A man traveled from Cache Valley to suburban Houston in 2014 and stalked his ex-wife’s family for two days before killing six of them as part of a plan to harm anyone who had helped his former spouse, a Texas prosecutor said Monday.

Ronald Lee Haskell lived with his family in Logan but had a history of domestic violence that eventually led to divorce. His ex-wife and their children moved to Texas to live near her family, Harris County prosecutor Samantha Knecht said during opening statements in Haskell’s capital murder trial.

Haskell confronted Stephen and Katie Stay — his ex-wife’s sister — at their home in July 2014 and fatally shot them and four of their children, Knecht said. He also shot the couple’s oldest daughter, who was 15 at the time. She suffered a head wound and played dead before notifying police, according to Knecht.

Haskell, who turned 39 on Monday, took the Stays’ vehicle and was near the home of his ex-wife’s parents when police cornered him. Officers took him into custody after an hourslong standoff, Knecht said.

She said Haskell had intended to kill his ex-wife’s brother, who also lived in the area.

“This was a plan created in anger and fueled by vengeance,” she told the jury.

Haskell faces the death penalty if convicted of capital murder.

Defense attorney Douglas Durham told jurors that Haskell admits to killing the six but said he was severely mentally ill at the time and didn’t know his actions were wrong.

Haskell was a “very troubled and sick individual” who heard voices telling him that his family would return to him if he killed the Stays, Durham said.

Ronald and Melanie Haskell were married in California in March 2002, and public records indicate they may have moved to Logan in 2006.{/div}

In a search of Cache Valley police and court records shortly after the murders, The Herald Journal learned Ronald was first arrested in 2008 and charged with simple assault and domestic violence after Melanie Haskell reported that her husband struck her in the head and dragged her by her hair in front of their children. He entered a plea in abeyance to the misdemeanor charges, and both charges were later dismissed.

According to Logan Police Chief Gary Jensen, Haskell had a handful of other involvements with police, including a welfare check on Melanie Haskell in 2009, called in by her husband after she left the home for a short time. He told police she had left him a note that caused him concern for her.

In July 2013, six weeks before she filed for divorce, Melanie asked for a temporary protective order for the couple’s four children, ranging in age from 3 to 11. Part of that record references an investigation by the Division of Child and Family Services.

One month later, Melanie reported a protective order violation. It was stated Ronald had made threats against her to his attorney, police said.

In October 2013 she reported another possible protective order violation because Ronald had shown up at one of the children’s elementary schools. However, the protective order was actually served on the day of the complaint. Police said neither incident was prosecuted.

In the midst of these events, the couple had started building a home together in Smithfield and were required to provide much of the labor on the construction of the home. The family never moved into the home.