Who is responsible for the deaths in San Bernardino? The murderers.
Not the managers of apartment complexes -security cameras are not going to dissuade these people from shooting or stabbing their victims. While you are right, not every person killed in San Bernardino is a gang member, many of them are. And I fail to imagine that gang members preparing to shoot up an apartment would stop and reconsider because the apartment complex had put up cameras. The murder victims in this city are rarely randomly targeted. Often times the victims of attacks know their killers, yet even if they survive, they refuse to cooperate with the police.
Fining apartment complexes for renting to mopes is not a feasible option. Sure there are hundreds of slum housing areas in the city; but fining the owners is going to do nothing to encourage them to improve the quality of their complexes (as if that was a priority anyways).
Our fine city is unfortunately full of dangerous areas, and crime-infested apartments. The best advice for any person would be to move out of or not to visit apartments like the Meadowbrooks; you increase your chances of survival greatly by staying out of areas that get shot up on a weekly basis.