Conley was then sentenced to life in prison without the possibility of parole.
The repeatedly delayed trial got underway Tuesday, with just two days' worth of testimony cross-examined in court. Closing arguments took place at the beginning of Thursday, with the jury receiving the case soon after by mid-morning.
Despite the trial's swift timing, testimony and evidence presented by prosecutors illustrated a grisly scene played out based on an alleged plan.
During the first day of testimony, Valerie Jackson's mother told the court she received social media messages from her daughter with "911" repeated before the killings took place on Aug. 8, 2015. Another message read "DVD has a gun," which Barbara Yankse, Jackson's mother, said meant David Conley has a gun.
On the second day of the trial, photos were presented to jurors, showing the victims' bodies being handcuffed and restrained throughout their northwest Harris County home. Conley was seen to have no reaction to the images being displayed.
Conley was on trial for the murders of the two adult victims - Valerie Jackson and her husband Dwayne Jackson.
The deceased children in the case are Nathaniel, 13; Honesty, 11; Dwayne Jr., 10; Caleb, 9; Trinity, 7; and Jonah, 6.
PHOTOS: The victims who died in the Aug. 8, 2015, mass murders
Conley wasn't facing the death penalty. Conley's defense team said he is intellectually disabled, and the U.S. Supreme Court has ruled death cannot be a punishment.
SEE ALSO: Mass killing suspect speaks his mind in jailhouse interview
Jailhouse details from suspect accused of killing family
Eyewitness News has been inside the courtroom from the beginning of the trial. Get the latest movements in the case by following Steve Campion on Facebook, Twitter and Instagram.