You have freedom to sue him in front of a judge since he has committed an unethical thing which is prohibited in Islam. I think by raising the issue before a judge may protect other victims who might be attacked by him in the future.

 

Prophet Mohammad (peace be upon him) has explained that whoever commits fornication with the wife of his neighbor, that his sin is greater and worse than his committing the same thing with ten women. That is because it is of the major sins. Such is the case of one who abuses his relatives. The Prophet said to his companions, “What do you say about fornication?” They said, “It is unlawful as Allah and His Prophet have prohibited it and it is unlawful until the Day of Judgment.” He said: “A man who commits fornication with ten women is lesser to him than to commit fornication with the woman of his neighbor”. (Ahmad)

 

From `Abdullah bin Mas`ud that also said: A man said: “Oh the Prophet, what is a great sin before Allah? He said: to call God other than Him and He is the one who created you. He said: what else? He said: to kill your child lest he/she should share your food. He said: what else? He said: to commit fornication with the wife of your neighbor”. Then the Almighty Allah revealed its confirmation: {And those who invoke not any other ilâh (god) along with Allah, nor kill such life as Allâh has forbidden, except for just cause, nor commit illegal sexual intercourse and whoever does this shall receive the punishment} [25:68]. (Al-Bukhari and Muslim)

 

That is because it is his right to protect the dignity of his neighbor as he knows his (i.e. neighbor) entrance and exit. If an evil act is committed by a reliable and relative person its sin is greater. How about a person who commits this evil with his relative? How about a person who commits it with his own daughters? No doubt that his sin is great before Allah and before the people. All that happened to him due to a relapse in his innate character (nature) and crookedness in his behavior, although he behaves with people in a different way. The correctness of this man seems to be hopeless unless God wishes it. He is then considered to be abnormal, with a bad and crooked condition.

 
That is why the text came very clear that whoever happens to commit fornication with his unmarriageable woman its punishment is: he has to be put to death. The Prophet of Islam said: “Whoever happens to fall (in fornication/adultery) with his Mahram (unmarriageable person), so kill him”. (At-Tirmidhi)

 

It is raised to Hajjaj that a man committed fornication with his sister forcibly, he said: detain him and ask from amongst the companions of the Holy Prophet, and they asked Abdullah b. Mulassif who said: I heard the Prophet of Islam saying: “Whosoever transgresses the Muslims, make line on the middle of his body with a sword”. This means divide him into two parts with a sword”. This and the people similar to him whose innate character is relapsed, their punishment in Islam is to put them to death for their disgraceful crime with their inviolable (unmarriageable).

 

It is the responsibility of any Muslim who watches ore hears about a case to abuse to report it to the judge in order to protect others from anticipated harm which may be inflicted on other victims. The Muslim family must cuff off relations with those who are accused of abuse as a warning against them. We have an example in the Prophet who cut off his relations with three men who did not join with him at the battle of Tabuk.