When the dust settled, eight people were found dead inside with gunshot wounds to the head, and David Conley III was taken into police custody.
Family members tell us 40-year-old Valerie Jackson and Conley had a volatile on-again off-again relationship for about 15 years. Eyewitness News spoke with her brother, Earl Yanske, on the phone Sunday night. He says nobody ever thought it would end the way it did Saturday in Valerie's house with her, her husband and six of her children dead.
Family says at one point Valerie and Conley were married, and that they had two children together. Investigators say he killed one of those children -- 13-year-old Nathaniel -- in the rampage. Their other child lives out of state.
PHOTOS: Scene where 6 children and 2 adults were found dead
Yanske, who lives in Montana, tells us he called Conley at around 10pm Saturday while deputies surrounded the house.
"'I need to ask you something very serious,'" Yanske said he told Conley. "'Did you kill my sister?' And he said, 'Yes I did.' He said it very calmly."
Yanske tells Eyewitness News that before Conley climbed through a window to carry out his rampage, Valerie desperately tried to get help on Facebook.
"A family member of mine, who will remain nameless, yesterday morning -- received a message from Valerie by her Facebook stating that she should call 911 because David was there with a gun," he said.
She called, and investigators say deputies did a welfare check. Nobody answered the door so they left. They came back several times. Yanske says he believes they could've done more.
"They were notified in the morning about David with a gun. My sister sent the message stating he had a gun, and knowing the fact there was an active warrant on him," said Yanske.
Friends, neighbors and total strangers dropped flowers in memory of the children. The youngest was six-year-old Jonah. The oldest was 13-year-old Nathaniel.
"I've been telling everybody about this guy, for my kids to stay away from him," said one neighbor who didn't give his name.
"He was at our house after school was over. He spent the night a few weeks at a time. He just always wanted to be at our house," Celeste Rendon says of Nathaniel, or Nate as he was known.
He was one of her son's best friends.
"We had the last period of school together, then we always said we were gonna try to make it to the NFL together," Troy Myers tells us.
Hours after the most horrific scene anyone in this neighborhood could have ever imagined, Pastor E.A. Deckard of Greenhouse International Church led friends of the family in prayer on the doorsteps -- hoping to find some semblance of peace.
"My prayer is that the family, even in the midst of this horrible situation will feel the love of this community, and love of the city of Houston, and we'll come together and embrace them during this most difficult time," Pastor Deckard says.
David Conley III is charged with three counts of Capital murder. We asked the Harris County District Attorney's Office if they will seek the death penalty. A spokesman says that decision will be made months from now.
CPS told us Sunday afternoon that there had been previous involvement with the family. They are "evaluating any prior contacts with the family to ensure they were handled properly."
Tonight, family hundreds of miles away, and people in this quiet community continue the struggle to wrap their minds around this tragedy.