Legal Question in Personal Injury in Wisconsin

There are both potential criminal and civil implications to the situation you describe. If you want, you can go to your local police and/or your district attorney's office and file a complaint. If they are willing to pursue it, they will do the investigating and they will decide the charges. This criminal method is not you against your son. It is the state against your son for committing a crime. If found guilty, there could be jail time and other sanctions, including an order for him to repay what has been taken.

You could hire an attorney and go against your son in a civil action. That would cost money and not only the investigatory costs would be on you, but the burden to proove what you say occurred. This could result in a judgment that monies be repaid to you. If they haven't been spent and are recoverable, you may be able to collect them.

You could do both of the above at the same time or sequentailly. You would have to be careful to pursue claims before any statute of limitations expires.

Finally, you cannot threaten criminal prosecution in order to enhance any civil position you may have. That could be a crime of blackmail.

Your situation is complex and you should consult with an experienced attorney or law firm who could help you out.