In California, are apartment owners responsible for the safety of tenants?

Are california landlords responsible for the security of their tenants in environments known to have high incidences of crime, drug abuse and violence? Can anyone direct me to information sources regarding this issue? My landlords in a gated complex, with part time "courtesy patrol" have allowed trespers to enter the grounds, ault & har tenants, deal drugs from vehicles, and prostitutes solicit outside the gate. What recourse do I have to get them to act?