San Francisco is small compared to its metro area but is still a larger population within the city proper than Fresno. And, the city of San Francisco has very high demographics due to the high cost of living, the median SF house price is $730,000.
But the city of San Francisco actually has a higher per capita crime rate than the city of Fresno.
SF just hit 100 murders for 2008 out of a population of 765,000. Compare that to Fresno with 36 this year out of 470,000 people.
The high crime of San Francisco is limited mainly to the southeastern sections of the city proper but what happens there is so high that the per capita in the city of SF becomes higher than Fresno.
In Fresno there are large swaths of the most affluent areas (such as Fig Garden) that are actually county islands patrolled by the sheriff not the PD. So the low crime rates in those areas are not included in the city figures even though the city completely surrounds them.
And of course in Fresno there are bad areas where you need to be careful.
I'm not looking to argue about one city being better than another. There are many objective and subjective things that enter into the reasons people like or don't like an area.
But when someone says that Fresno is "crime-ridden" and "full" of gangs. Well I feel the need to point out that perception and media-reporting is not reality.
Fresno compares comparably with other cities that are considered "safer". For example, the cqpress link above ranks Fresno between Salt Lake City and Seattle in terms of crime.
There are areas in every city and metropolitan area that are crime troubled. But that shouldn't cause an entire city to labeled.
And yes I've done business trips to both downtown Pittsburgh (heck I'm an outsider who can even spell it right

) as well as outlying areas like Washington. I've even spent trips across the state line staying in Youngstown, Canton, etc. I like the area, I'm not one who will say bad things about it.