Legal Question in Family Law in Massachusetts

Is your step father the biological or adoptive father of your sisters. If so, you will have to prove he is unfit and that could be both difficult and expensive.

If he is neither the biological or adoptive father of your sisters, then your case gets easier. I assume your sisters are the biological children of your mother.

I would do two things, first try to find out where your sisters are and second contact an experienced attorney who deals in custody battles. I do not handle custody battles like this.

However, if you cannot find someone, I will attempt to refer you to someone who does this work.