1. Do mixers know where they're getting a deposit from?
2. If yes, will they co-operate here with the officials and let them know about the deposit?
3. If they do, how will they stop the scammer from moving his funds out of their mixer?
There is a lot of mixing companies now but I doubt they will have the same answers to these questions, soI will just speculate because all the answers given here are not officially coming from the mixers team
1. Do mixers know where they're getting a deposit from?
There are mixers where the mixing is all automated and there are mixers where they can trace the addresses before they get into the pool
2. If yes, will they co-operate here with the officials and let them know about the deposit?
They serve their clients and they are not regulated to have an obligation to any entities or authorities because there is none on their TOS that says what kind of funds or clients will their mixers accept, this is not an exchange where clients are subject for verification
3. If they do, how will they stop the scammer from moving his funds out of their mixer?
They may or they may not it will depend on how they will address this issue when they are called up and prosecuted.