Does my cousin have schizophrenia and what should i do?

recently my cousin has moved in with me.. he is 20 years old and just in the past 3 months he has began talking "crazy" saying off the wall things.. having conversations with no one, having the wierdest conversations i cant even begin to explain. he has became angry 2 times so far to the point where i have had to stand up and get in a defensive position because i thought he was going to attack. i dont know what i should do im 19 years old and im trying to convince my mom to do something about this but she just doesnt know what to do either. he has also said stuff about "shooting people" and im just trying to figure out if i should sleep with 1 eye open. please help