Man charged with six US gun murders
A man has been charged with killing four children and two adults in suburban Houston in the US.
Haskell is also accused of critically wounding a 15-year-old girl in the attack yesterday evening.
Mr Hickman said Haskell has been charged with multiple counts of capital murder.
The officer corrected an earlier report that said Haskell was the father of the children. He said the adults killed were the children's parents.
He did not release details of Haskell's relationship to the family. He was arrested after a stand-off with authorities lasting more than three hours.
"I have not personally in 40 years seen a tragedy in one family that is this horrific," Mr Hickman said.
Documents introduced during a preliminary court hearing allege that the 15-year-old girl attempted to close the door to the home after telling Haskell her parents were not there but he kicked the door in, KPRC-TV said.
Haskell was estranged from a woman related to the couple, Mr Hickman said. Authorities said earlier that his wife lives in another state.
The children include two boys, aged four and 14, and two girls aged seven and nine. The father was 39 and mother 33, according to Harris County Sheriff's Deputy Thomas Gilliland.
The gunman "gathered up the children that were here and awaited the arrival of the parents", Mr Hickman told reporters outside the home. "Some time later the victims were shot in the residence."
Mr Hickman said Haskell "came in the guise of a FedEx driver wearing a FedEx shirt". It was not clear whether he was a FedEx employee.
The officer said that after Haskell left the home, the injured teenage girl - a daughter of the murdered couple - contacted authorities telling them the gunman was en route to shoot other family members.
Police located Haskell's car and a low-speed chase ensued that ended in a cul-de-sac, Mr Hickman said. A stand-off ensued lasting more than three hours before Haskell exited the car, sank to his knees and surrendered.