A mother who shot and killed her two daughters allegedly planned the murders at least two weeks before, say Henderson County authorities.

"It appears she also intended to kill her husband, but the entire crime did not go as planned," said Sheriff Botie Hillhouse, in a statement released Friday.

Hillhouse said they discovered the mother planned the murders during an interview in which 29-year-old Sarah Nicole Henderson confessed to shooting her daughters, 5-year-old Kenlie and 7-year-old Kaylee.

The two girls were found dead inside a residence just outside of Payne Springs early Thursday morning.

Authorities said they were first called to the home three hours before on a report of a possible suicidal female. Upon their arrival at about 11:45 p.m. Wednesday, deputies talked with a male and female at the residence who told them everything was OK.

“No one was in any danger," Hillhouse said. "No one was suicidal, no signs of violence, no signs of anything.”

At 2:24 a.m., another 911 call was made from the home. This time the caller reported his wife shot her two children.

A family member told WFAA that Henderson was acting erratically over the last couple of weeks, but no one imagined she would shoot her daughters. Deputies say hours before the shootings, she was talking about people being after her.

Henderson was charged with one county of capital murder and is being held on a $2 million bond. Another capital murder charge is pending as Henderson remains under a suicide watch at the jail.

In 2010, Henderson was investigated by Child Protective Services, according to Marissa Gonzales, a spokeswoman with CPS. However the details of the case are confidential.