The family of Jayme Biendl contends that system failures helped the inmate commit murder.
The Daily Herald reports that the lawsuit filed Tuesday in Snohomish County Superior Court is the first time Biendl's family has publicly criticized the department and former Monroe Correctional Complex Superintendent Scott Frakes.
Corrections Department spokeswoman Norah West declined comment.
The lawsuit blames the state and Frakes for not doing enough to protect Biendl. It says it was "highly predictable" that safety lapses in the prison "would cause harm to employees."
Byron Scherf has been sentenced to die for the killing but is appealing his conviction.
When Biendl died, Scherf was serving a life sentence for his violent attacks against women.