People with schizophrenia are usually not violent. A very small minority of violent acts that occur are caused by people who have schizophrenia. Like anybody, if you are afraid, you're more likely to act out in a violent way. People who have schizophrenia sometimes have paranoid delusions where they feel people are out to get them, or they hear voices that tell them people are out to get them and they need to defend themselves, and so sometimes that leads to violence.
But, it's still extremely rare for a person with schizophrenia to act in a violent way. When they do, it's more likely to be in their home with a loved one than with strangers. That's just like everyone in the population; you're more likely to hurt someone who's close to you than a complete stranger.
It's substance use and substance abuse that leads to the increased risk of violence, both in the general population and in people with schizophrenia; it increases the risk quite a lot. Managing substance use, both in the general population and in schizophrenia, would be one way in addressing the risk for violence.
People with schizophrenia have been portrayed as being violent in the media, but it's really important to remember that that's not accurate, that most people with schizophrenia do not commit violence and are not violent people.