It alleges officials ignored warnings about Williams, a convicted sex offender transferred under the state's gender-identity housing policy, and seeks damages plus an order blocking the policy.
The complaint says other women have faced assault, threats and harassment from male inmates housed there; the corrections department declined comment and said Williams was moved last October.
Can prisons protect female inmates without violating the constitutional rights and safety of transgender prisoners?
Was the attack in a women's prison a predictable policy failure or an isolated security lapse?