Just beating a dead horse now but DC is not really different from other big cities. The majority of the city, and virtually all the areas tourists and federal officials go, is very safe. Crime is possible anywhere, but you're no more at risk in those places than you would be in a small town. DC does have some extremely rough and dangerous neighborhoods, just like Baltimore City, South Boston, the Southside of Chicago, etc., etc. These neighborhoods have been plagued for decades by a horrible combination of gang control, guns, drugs, failing schools, and one (or no) parent families because so many of the dads have been locked up. Anyone who figures out how to fix those areas will truly deserve a Nobel Prize, because nothing we've tried has made a huge difference so far.
I'm 100% certain Trump's law enforcement push will have no impact on crime rates in DC's eastern and southeastern neighborhoods, and those are the only areas in DC where crime is a major problem, statistically speaking.