A preliminary autopsy indicates a state social worker whose body was found along a country road was strangled, the county sheriff said Thursday.

Sally Blackwell had received threats related to her work, authorities and relatives said. The case was being investigated as a homicide, police Lt. Mike Hernandez said.

Family members reported Blackwell, a Child Protective Services program director, missing after she didn't show up for work Tuesday morning. County employees found her body Wednesday.

Tina Taulbee said her stepmother had spoken of threats she had received.

"In the 15 or 16 years she has been there, this is the first time she was actually scared," Taulbee said.

The autopsy findings were announced by Victoria County Sheriff T. Michael O'Connor.

CPS investigates reports of abuse and neglect of children, and, if necessary, places them in foster care.

Blackwell, 53, oversaw 46 caseworkers, their supervisors and support staff in nine counties.

Agency spokesman Patrick Crimmins said in a statement that CPS employees are trained how to deal with hostile clients and manage their personal security when visiting homes.

Blackwell's family is offering a $5,000 reward for information that leads to the killer's conviction, said her niece, Holly Tachovsky.