Houston: A 49-year-old man held in the US state of Texas in connection with the murder of eight people, included 6 children, has been identified and is charged with three counts of capital murder.

David Conley, who has a violent criminal history, fatally shot each one of the victims in the back of the head yesterday after tying them up at their home where he had lived formerly.

The deceased, found in each of the three bedrooms of the house, have been identified as Dwayne Jackson, 50, Valerie Jackson, 40, and six children - Nathaniel, 13; Honesty, 11; Dwayne, Jr, 10; Caleb, 9; Trinity, 7; and Jonah, 6. Harris County Sheriff's Office Deputy Tim Cannon said the authorities will investigate why Conley committed the murders, but may never know.

"This is one of those that is unexplainable, why this person got to the point where he had to murder his relatives and children, we don't know," Cannon said. "When it comes down to law enforcement trying to predict what would happen, I wish we had that type of intuition where we could look that far and see into someone's mind, he said.

However, the detectives say the motive appears to be a dispute with Valerie, with whom Conley had a previous relationship. They say one or two of the children may be Conley's. Conley, who is being held in Harris County Jail, did not appear in court and the judge denied him bond. An attorney is not yet listed for him.

Conley told police that he discovered on Saturday morning that the locks had been changed at the home after he had moved out. "He restrained, shot and killed eight people," said Celeste Byrom, an assistant district attorney, during a brief court hearing. Valerie, had recently changed the locks, but Conley was still able to get inside the home as a window had been left unlocked, according to a prosecutor.

The prosecutor recounted Conley's statement to investigators that he broke in through an open window after Valerie, whom he formerly lived with, had changed the locks. Conley told investigators that he restrained eight people inside, including Jackson and a 6-year-old boy, and shot them in the back of the head, prosecutor said.

Court records show that one capital murder count covers multiple deaths. Another capital murder count is for a person under 6 years of age. Authorities had been called to the home for a welfare check.

Doctors at the scene in Falling Oaks, near Veterans Memorial and Fallbrook Drive, said all eight victims suffered gunshot wounds to the head and died at the scene. Conley, who was arrested after surrendering, was wanted on a warrant assault on a family member.