Upvote:2
Here are few things that my help
- Check where the large international chains have hotels (Marriott, Hilton, IHG, Accor, etc). If an area doesn't have any of these at all, it's either not very attractive or not safe.
- Before booking a hotel, read reviews on Tripadvisor (or equivalent). If the neighborhood is unsavory, it will show up there.
- Google "Travel safety Washington DC" . There is generally good info on the first view links
Of course, there are always exceptions, but I found this works fairly well