HOUSTON » Neighbors of a family fatally shot in a Houston home were aware the household had problems, including a history of domestic violence, and worried about the six children who lived there.

Carlos Sanchez, 40, who lived across the street from the family, recalled once finding the oldest child, 13-year-old Nathaniel, after dark on a street in the neighborhood. The teenager said he was running away. Sanchez took the boy home but was surprised by the reaction of the father, David Conley, after telling him his son had tried to run away.

Conley "didn’t say nothing. He just looked at me. The kid went inside," Sanchez said. "(Conley) was already in a different world."

Conley, who has a violent criminal history, faces capital murder charges after his arrest Saturday for the deaths of Nathaniel; his five siblings, 10-year-old Dewayne, 11-year-old Honesty, 9-year-old Caleb, 7-year-old Trinity; and 6-year-old Jonah; their mother, Valerie Jackson, 40; and her husband, DeWayne Jackson, 50.

Conley, 48, stood handcuffed and shackled and said little during his first court appearance Monday. His court appointed attorney, Joseph Scardino, didn’t return a phone call seeking comment.

The family members were all shot in the head. Nathaniel was believed to be Conley’s son from his relationship with Valerie Jackson; the other children were Valerie and Dewayne Jackson’s.

Harris County District Attorney Devon Anderson said authorities were alerted to what was happening in the family’s home on Saturday when Valerie Jackson sent a text to her mother, who lives in another state, saying she was being held at gunpoint.

Deputies forced their way into the home later Saturday but retreated after Conley fired on them. Conley eventually gave himself up, allowing deputies to enter the home and make the gruesome discovery. Most of the victims had been handcuffed and some had been shot multiple times, police have said.

"My heart goes out to that family, what they are suffering today," Anderson said.

The Harris County Sheriff’s Office has said problems between Conley and Valerie Jackson might have led to the shooting. The relationship between them had recently ended.

Last month, Conley was charged with assault after allegedly pushing Valerie Jackson’s head against their home’s refrigerator. In 2013, Conley was charged with aggravated assault for threatening Jackson with a knife. He pleaded guilty and was sentenced to nine months in the county jail.

Vilma Flores, 61, who was the couple’s next door neighbor, said she worried about the children as they were sometimes left without adult supervision. Sanchez said he would sometimes see the youngest child, 6-year-old Jonah, playing in the street with his siblings and no adults around.

Estella Olguin, a spokeswoman for Child Protective Services, said her agency had been involved with the family, but she declined to offer details.

Sanchez and other neighbors questioned why authorities didn’t go into the home sooner Saturday, knowing the family’s troubled history and Conley’s violent criminal record. Neighbors said they saw deputies come to the home at least twice earlier in the day, knock on the front door and leave when no one answered.

Sgt. Craig Clopton, the lead investigator, said Sunday that he couldn’t "reveal the exact parameters of those decisions."

"There are certain circumstances when we can make entry and certain circumstances where we can’t. Even though we want to, sometimes the law prohibits that. … It wasn’t until officers looked in the window and actually saw somebody injured that the decision was made that now we have enough to go in."

Investigators have declined to say when on Saturday the victims were shot or if any were alive when deputies first tried to enter the home.

Anderson said her office hasn’t yet decided whether to seek the death penalty against Conley.