How can i live with this?

yea well my step dad i cant stand him...he makes me and my moms lifes miserable! he is illegal and sometimes i just want to call the police on him. i dont know what to do my mom doesnt want him either. but he wont leave he says he says to my mom well im your husband and now you got to live with it...wtf! no we dont. he has tried to hit my mom that stupid *** i hate him so much what should i do??? should i call the police. i dont want him to know it was me im even scared of him!!! help!