The problem is that criminals are not effectively punished in America. That and many gang bangers under 18 who murder are let go with a slap on the wrist.
I think that if the city was able to deal with the endemic corruption and financial mismanagement then more police and other services would be addressed. More cops on street beats walking around these high crime areas would do a lot to intimidate criminals IF real punishment was meted out to these punks.
San Diego has a very bad drug and gang problem that is has not dealth with in an effective manner yet. I would never buy downtown or in Hillcrest/Northpark with the massive amount of gang activity and theft. Same counts for places in North County like Oceanside and Vista.