Police said Ronald Lee Haskell was dressed as a FedEx delivery man when he knocked on the door of his former in-laws’ home in a Houston suburb Wednesday evening.

Fifteen-year-old Cassidy Stay answered and told him that her parents weren’t home. When she tried to close the door, he forced his way in, the Associated Press reported.

Haskell, 33, was reportedly searching for his ex-wife, who police initially said lives out of state. Neighbors said their marriage had been so shaky that his ex-wife’s sister, Katie Stay, traveled to Utah last fall to help her sister escape the marriage and get a fresh start in Texas, the AP reported.

Thursday, police offered the details. In their home in the northern Houston suburb of Spring, Haskell tied up Katie Stay, her husband, Stephen Stay, and their five children, who ranged in age from 4 to 15. He put the family face-down on the floor. And when the family refused to tell Haskell where his ex-wife was, he allegedly shot them in the back of the head.

The slain couple’s teenage daughter, Cassidy, suffered a fractured skull when a bullet grazed her head, the AP reported. She played dead until Haskell left and then called 911 to warn police the suspected shooter was on his way to her grandparents’ home to cause more harm, the Houston Chronicle reported. Both parents and the other four children were killed.

The children who died were Bryan, 13; Emily, 9; Rebecca, 7; and Zach, 4, according to the Chronicle.

Harris County Precinct 4 Constable Ron Hickman told The Washington Post police intercepted the suspect en route. And, after a 25-minute pursuit followed by a three-hour standoff with police, deputies placed him under arrest. Haskell is charged with multiple counts of capital murder, police said Thursday.

“Stephen and Katie Stay and their beautiful children were an amazing and resilient family. They lived to help others, both at church and in their neighborhood. We love them beyond words,” Katie Stay’s father, Roger Lyon, said in a statement released Thursday. “Cassidy Stay, 15, who survived the attack, is expected to make a full recovery. We are grateful for this miracle. 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. More information will be forthcoming in the days ahead about her heroics, but right now we want to concentrate on getting her well.”

Haskell has had a series of run-ins with law enforcement.

While living in Utah in 2008, Haskell was arrested on suspicion of domestic assault and domestic violence. His then-wife told police he dragged her by her hair and hit her in the head in front of their children. The case was dismissed as part of a plea deal, the Salt Lake Tribune reported. Then last year, she obtained a protective order against him.

A divorce decree issued in February stated Haskell and Melanie Kaye Haskell were married in 2002 in Orange County, Calif., the AP reported. A judge granted joint custody of the couple’s four children, ranging in age from 3 to 11, giving Haskell’s ex-wife primary custody.