Disrespected by brother-in law :'(

Hailey • Mother of 3 amazing children! 👦 03/04/10 👧 04/29/12 👶 01/07/16 ❤️️
I am so beyond upset!
My husband and I took in his 16 year old brother in March because of family issues. Since day one it's been so stressful. 
I had to go out of town for a night with my two children and my neighbor calls me telling me there are a dozen teenagers in my house and they are SMOKING in my home, I was devistated! I bursted into tears, I've never been so disrespected!
I tell him I'm calling the cops and every person in my house needs to get out NOW! 
How dare he do this! We bring him into our home when he had nowhere to go, take care of him and the second I leave the house he brings delinquent strangers into my home and desecrates my children's things with smoke!! 
I feel so betrayed! 
Please tell me what I should do?!