"I could smell ... (alcohol) on him, and his actions indicated to me that he was intoxicated," Murphree said. "There's nothing right now to indicate that it was an intentional homicide, but the investigation is still ongoing."
Watrous was being held in Denton County jail on charges of manslaughter, criminal negligence and tampering with evidence. Bail was set at $230,000.
Watrous' attorney did not immediately return a call seeking comment Wednesday. A contact number for Washburn-Rives could not immediately be found.
According to court records, Child Protective Services have been investigating Watrous and the girl's mother, 29-year-old Brandy Michelle Washburn-Rives, on child abuse and neglect allegations in Texas and Oklahoma since 2003.
The agency found in March that the father had abused a child from a previous relationship.
Denton County court records show that authorities arrested Watrous in April on a charge of injury to a child, but that a grand jury declined to indict him.
CPS spokeswoman Marissa Gonzales said she didn't know of any attempts by the agency to remove the children from Watrous' home after the March investigation.
Authorities arrested Watrous Friday. The affidavit said Washburn-Rives told a caseworker she was at Watrous' home hours before the shooting and saw him drinking beer.
Police say Watrous was recklessly handling a revolver at his home when it discharged, and that Ashley's 9-year-old brother and 1-year-old sister were present when the girl was shot and killed.
Murphree said Watrous tampered with the evidence by moving the weapon from the crime scene and locking it in a gun safe.
Watrous has five children. According to court records and police officials, Ashley was one of three who lived with him. The other two living with him -- a 9-year-old boy and 1-year-old girl -- have been placed in foster care.