A timeline released Thursday
casts new light on the case, and adds fresh fuel to a question reporters have been asking since the grisly slayings were discovered on Sunday
: Could anything have been done to prevent the massacre?
In a statement, the sheriff's office said 911 dispatchers had received reports that a woman at the house had "sent concerning messages via Facebook and SMS Text to family members in states outside of Texas." These messages prompted a series of welfare checks on the home.
According to the Harris County Sheriff's Office, dispatchers got their first request for a welfare check for the home at 10:42 a.m. Saturday, and deputies arrived at the home about seven minutes later.
They also responded for requests for welfare checks at the home and arrived at 4:43 p.m. and 6:10 p.m., the timeline says, giving the same description of what deputies observed during those three checks: "No response from inside the home, home secured."
They headed back at 8:55 p.m. after another welfare check call to 911. At 10:26 p.m., they observed through the window that one person had been killed, then they forced entry into the home.
The suspect started shooting from inside the house, forcing them to pull back and wait for hostage negotiators and a unit that specializes in high-risk situations, the timeline shows.
It wasn't immediately clear what time the victims -- two adults and six children -- were killed. Suspect David Conley was taken into custody at 11:58 p.m. after the hostage negotiation team convinced him to surrender.
Conley has been charged with capital murder and is being held in the Harris County Jail without bail. Investigators accuse him of handcuffing his victims, then shooting them.
Asked on Sunday whether authorities could have entered the house sooner, Harris County Sheriff's Chief Deputy Tim Cannon said he couldn't provide many details but suggested that deputies' hands were tied.
"There certainly comes a time in any law enforcement's career that we're going to run across something where we think we might could do something but the law may restrict us from doing such," he said. "In this situation, I can't go into too much detail about it right now, the officers on the scene did not have enough information at the time to make forced entry into the residence."
Authorities said "exigent circumstances" led them to enter the house.
"Repeated attempts to make contact with residents inside the Falling Oaks home went unanswered, until visibility changed allowing deputies conducting a perimeter search of the premises to observe the body of a deceased individual inside of the home," the sheriff's office said, adding some details were omitted from the timeline due to an ongoing investigation.
Earl Yanske, whose sister Valerie Jackson was among the victims, said he believes deputies could have done something to stop the gunman before it was too late.
"A family member of mine, who will remain nameless at this time, (Saturday) morning received a message from Valerie by her Facebook stating that she, the person, should call 9-1-1 because David was there with a gun," Yanske told CNN affiliate KTRK
That was one reason deputies did a welfare check at the house, Yanske said, but they left when no one answered the door.
A legal analyst for CNN affiliate KPRC
said it didn't appear deputies could have done anything differently.
"If they don't have probable cause to believe that anyone inside that residence is in harm's way or needs their assistance, then the law says they don't have the right to kick that door," attorney Brian Wice told KPRC. "They don't have the right to do anything more than to knock on the door, or look into a window."