My question involves criminal law for the state of: New York
Recently, my wife found out that her 22 year old half-sister (on her Mother's side) has been having intercourse with her father, which began as molestation when she was 8 years old and has continued through the years. Furthermore, my wife herself was molested by the same man (her step-father at the time) between the ages of 4-6 before she told her grandmother. My sister-in-law had not told anyone about the relationship until a recent boyfriend, who has brought it to light. Upon revealing this information to other family members, we all discovered that 2 of his other children had been molested by him over the same time-frame, and he recently has tried to have sex with yet another of his daughters, who declined and stopped speaking to him. All of this has happened while he still remains on the sex offender registry with the highest risk level of repeating.
My wife's grandmother contacted the authorities, who opened an investigation, interviewed his two youngest daughters and my sister-in-law's boyfriend. He attempted to interview my sister-in-law, who would not get back in contact with him. We tried to convince her to turn him in, but she refuses, as she doesn't want her younger sisters to see their father in jail. His youngest daughters both told the investigator that nothing had happened, but he expressed very clear doubt. We last heard from the investigator over a week ago, as he told us that while there likely was molestation happening, there is nothing that can be done about it unless a victim gives their statement and the molester confesses. The only proof we have at this point is text messages from my sister-in-law and a video recorded by her boyfriend of her confession.
At this point, all of his victims refuse to give a statement out of empathy for him and a fear of shame (we feel there is a brainwashing/Stockholm syndrome element as well). However, we know he is still hurting young children and it needs to stop. What are our legal options going forward?
Thank you all in advance for any help you can give us at this point!


