Mom with Alzheimers, a banker brother -n-law/wife who spent all her money, screwed mom and family. What can I do?

I have a mother in law (now 80) has Alzheimer's as a result of a fall last fall. She has 2 children, both male. Her youngest son has POA for health and finances because he is the "banker in the family". About 10 years ago, the house where she lived was placed into an LLC-she sold the house to my husband and his brother. About 5 years ago, her home was sold, at closing there was $266K. At the time of sale, my husband and I found there was 3 liens against the home totaling $244K. When my mother in law bought the home, it was paid with cash from the death proceeds of the their father. The youngest son, took loans out against the home to build his mcmansion. So, in order to have the liens lifted at closing, he took the money and placed them into a CD to be held as collateral for one year against the other loans he took out. In addition, he stated that my husband received $76K as a disbursement from the sale of the home noted on a K-1 form and they told us, the closed the LLC out without telling my husband. We did not receive any dollar amount what so ever. So my brother in law and his wife lied to the IRS. Thirdly, I needed to refinance my home, as a result of a lay off- I bought before I married the eldest son and the service provider stated there was a disbursement of $76K we took that was filed from a K1 form, I needed to disclose. I requested from my brother in law as to where the money went, I was called names and he refused to provide me with documentation. So as a result, I lost my home, my kids could not receive college financing and it has affected my ability to find work in my trained field. The money is all gone that was intended to pay for moms care. My mother in law is renting an apartment in an independent living community on the 4th floor. My brother in law refuses to buy the life line system because of cost. Over the past few months I have seen a marked decline in my mother in laws health, she falls all the time, she is shaking terribly, she has a walker, but can barely use it without tripping over it. Shes in bed by 7pm or at least in PJs by 6pm laying in bed. She can barely put a shoe on, her clothes on or even use the bathroom without it taking a half hour to pull up her pants. As far as eating goes, she gets one meal a day from the kitchen, she has now resorted to frozen meals or sandwiches for other meals or splits the meal received in half and makes 2 meals because she cant cook for herself like she used to. By brother in law is trying to get past the look back period so he doesn't have to disclose where all the money went. He and his wife are both corporate commercial and residential lenders for 2 major banks in the city where I live and know how to work the system. I want my mother in law evaluated for nursing home placement. She has become just short of a hermit where she lives. My husband doesn't do anything or say anything to his brother, cause he doesn't want to upset him. I am just beside myself in what to do for his mother but also I want them to disclose where the hell the money went. I need to help my mother in law...Help!!