DYFS cannot be sued for certain things but can be sued for others. You need to post this where a attorney that practices civil litigation or social service law can answer. it is not a criminal law question.
Back in 2009 they were sued and settled with a family for $600k in a widely publicized case involving abuse (although wrong doing was not admitted). As the other's have stated, you need to speak with an attorney as there are many specifics that will determine whether you have a viable suit or not.
Krekor Law 800-630-8284. Any answers posted on this site should not be construed as creating an attorney client relationship. Portions of this website may constitute and Attorney Advertisment. Before making your choice of attorney, you should give this matter careful thought. The selection of an attorney is an important decision.