<human>: Could you distill the essence of the text into 1-3 sentences?

My brother told me that he thinks about killing people all of the time. 
He was taking medication, but my mother recently told him to stop after two weeks. 
He said he specifically thinks about killing our grandmother by pushing her down the stairs. 
Recently my mother was crying and he told her to leave the room because she was bothering him. 
He says that all people are stupid and that he is above them. 
I tried calling my mother just now and she is not working with me when I say that we need to act and get him help. She says we should wait until Wednesday when he has a scheduled visit with a therapist. 
I think that will be too long and that we need to act now. 
I believe that he is actually serious when he says these things. 
I am in another state and do not know how to proceed or how I can legally help him. 
Do I call the cops? Can I get him committed to a hospital? I am so confused on what I should do. 
He said he told his therapist that he wants to kill people and that they did nothing. 

Help? How do I handle this?
<bot>: I think my brother is a sociopath and he says he wants to hurt people. I do not know how I can help as I am 1500 miles away.