Would it be petty to call CPS and the police on my BIL and oldest Step Nephew for drugs and distribution when my sister leaves him with my nieces?

My BIL is a piece of garbage trailer white trash gutter dweller... he and his 18 year old son have sold drugs and gotten high in front of my toddler nieces.. he smokes cigarettes around them and screams at them if they make any sound... he has mentally abused my sister for 7 years and she is finally getting the courage to leave in a few days via escort... would it be petty to call CPS and the police on his ass for all that I know? He has 3 other kids by another woman living there that he doesnt care what they do.. I think they would be better off with their other aunt who has raised concern and their grandmother...

Thoughts?