My friends brother in law stole 6000 dollars from his mother in law he lives with her and his wife and kid?

i hear that the guy moved in with his wives parents cause he coudnt afford a house and he is a drug addict and alcoholic she said he took money from his wife before for drugs (about 1000 dollars) and that he was acting strange for a few days while her wife and 6 year old son slept in the basement of her house! my friend later said when she went in her drawers she lost a box of money 6000 dollars worth and there was no one else in the house except him and his wife(daughter of the women) his 6 year old was at school at the time! and she doesnt think that a burglar went in one of her drawers and took the cash! so does this women call the police or go to court? the wife also believes her drug addict husband took the cash did soemthing with it and so does his dad in law so what do they do? go to court? my friend said he wants to press charges or do something about it at the same time he knows that he has a serious drug problem etc and stole money before! i dont know what the hell id do id probably call 911 call lawyer etc? what woud you do if something similar happened in your family???