The wanna-be gangster I spoke of was white. I live in one of the whitest regions of the country, but we still have gangsters, ne'er do wells and generally bad people here too. Everywhere does.
In the context of this thread, which is about whether people leave cities under the guise of doing so for safety to excuse the real underlying reasons of racism, this answer isn't that satisfactory.
It's the reverse of "I have a black friend". It's "I was scared of white people too". Obviously only you can know the true reasons, but please don't think that just because you made a decision for one set of circumstances that no one made the choice for other reasons.
Instead of relying on anecdotes you can look at the data which shows that white people do leave areas in cities with more black people in them. The data is not described by pure economics. The evidence is that some people are making the conscious or unconscious decision to racially segregate.