Sister has guardianship over father and she gives him a weekly amount of $250. We just found out that brother is coming over weekly and taking money from him. Even going into his wallet and taking it out. We know talking to him won't help as he has been taking and given to all his life. Should we call the police or make a complaint with APS?
Begin with a family intervention, if so, and publicly reprimand him. I'd also make sure that he is not allowed time alone with dad when he visits. Or, that you remove dad's wallet before he comes over. I am assuming dad lives with someone.
Regarding getting APS or the police involved, that's your decision. I think it is rather severe as you and your siblings can put controls like the prepaid credit card, auto bill pay, and paying coffee shop in advance.
We got to the point with Mom where we were paying for everything - and she had auto bill pay.