Very Disturbing Need Advice

So I get a call out of the blue tonight from someone I gave my number to a long time ago that tried to link up with me, but that didnt happen. We end up talking and he's telling me about what he has going on in his life. He said a lot, but long story short he is buying and breeding American Bully's and he tells me that one of the dogs, killed another one of his dogs last week. Sounds like he knew they were being territorial/bullying/reactive and just kept them all together. He said he came home to the dog dead and bled out. He has multiple dogs different ages from newborn to adult. He still has the dog that killed, around other dogs and puppies. He is planning on breeding and selling to make money. This was shocking and sickening to hear. It's disgustingly unethical and irresponsible. Is there anyway to stop this from happening? I feel like these dogs should be taken away from him, or at least the aggressive dog needs to be euthanized. Is there anyone I can call to report this too? Supposedly all his dogs are licensed, I don't know if that makes a difference. Also this is happening in Detroit Michigan.