There are a lot of posts recently on if DC is safe. I've lived here most of my life and I will firmly stand by the following.
DC is not THAT unsafe of a city. Generally speaking (very generally) if you are NORTH of Independence Avenue you will be ���safe���. If you are WEST of the Supreme Court you will be ���safe���. However there are some nice places like Eastern Market that are EAST of the Supreme Court (and in Northeast). There are pockets of "badness" even in Northwest. But generally if you are smart you will be fine. Just use common sense. (Southwest is a very small quadrant. It���s not that bad of a place.)
In any city be it LA, Houston, Miami, NYC certain street-smarts are necessary in order to 'be safe'. You might be used to flipping through your wad of cash in the farm areas of Kansas but it's not a good idea in the city.
When you walk down the street at night look as if you know where you are going and don't just stroll around.
Don't deliberately make eye contact with anyone ���shady���.
Don't give street people money.
Don't take short cuts through alleys.
If you don���t know where you are going take a cab rather than walking.
PAY the extra few dollars for some place to stay that you KNOW is nice and in a good location rather than saving a few bucks for a questionable place.
Park in a garage or on a well lit or well traveled street.
Remember thieves are opportunists. Even in the safety of the Mall and the Smithsonian museums you could be robbed or something else ���unsafe��� could happen.