Start planning your will. No one who ventures into the city makes it out alive.

But seriously, people who live out in the boonies or live sheltered lives always fear monger about the dangers of any city. People told me the same thing about visiting New Orleans, which is a LOT higher on the crime/capita rate. Nothing happened, didn't see anything happen. I did see a lot of people walking around with dogs, children, & grandparents eating beignets and what not. DC is the same and if you are sticking any of the main areas you'll be fine. Don't go venturing out into some sketchy neighborhood, just as you wouldn't anywhere else in the country.

The most you'll probably see is some obnoxious person randomly yelling in the street and drunk millennials loudly enjoying brunch. Pick out one of the many great restaurants, enjoy the free museums, tour the sites a bit. You'll be fine lol