That is the first time I actually heard that. I don't think there is much truth to that.

L.A. is not my favorite big city. It is simply too big for me to feel comfortable. As with any big city there are good and bad neighborhoods, but I have never heard of a "Danger Zone".

Statistically a city of that proportion has more murders than other cities and probably a few more problems, but you should be safe visiting L.A.. I guess you should stay away from South Central L.A.

I have been to L.A. many times and never crossed a "Danger Zone". 

I have been to L.A. as well and it does have a few shady spots but would not exacally call them dangerous being there are so many tourists around.

I live in Los Angeles. Yes there are pocketed areas. But generally these spots are not tourist attraction areas or close to them. So no need to worry. And these incidences are so random. These things are usually gossip or things seen through television.

Is there anywhere in particular you would like to visit in Los Angeles and I could tell you whether to avoid it or not?

I guess every place would be a danger zone if you won't be careful. As long as you avoid the places that you feel are not safe then you would be safe. And try to remain as simple when going to another place so that you wouldn't be a pick for the bad people in that place.