Can a landlord and/or apartment mgr. be responsible for the death of someone if the allow gangs to hang out on their property and innocentgets killed.

My son was murdered where he resided. The landlord and onsite mgr. Did nothing to clean up the property. My son was not a gang person. As a matter of f as ct he won sailor of the year 2 times. Has his own line of hair care products. A great barber getting ready to become barber instructor and otherbdreams gone. Because these gang members robbed and murdered him. Negligence? Arrests have been made gunmen. But the landlord may even befriended gang members.Eunice