The gun topic is certainly a controversial one. I live in Los Angeles and spent 20 years in the security business and am well versed in guns. Based on my experience, I would suggest the following.
1) Work with local law enforcement. Hold a community meeting, invite them to attend and explain your issues. They will help if given an understanding of the situation.
2) Less than lethal weapons are great unless you need a lethal weapon
3) Guns are unfortunately a necessary evil in many places. Take classes, buy something that you are comfortable with and keep it in a lockbox. This is a handgun requirement in California.