in 1990 DC was the murder capital of the world. 482 in 1991. It was a term used by Marion Barry.
It's important to know... most MoCo/DC people don't know this but.... "Prince George’s County is one of the richest majority-black counties in the U.S., with five of its communities topping a 2014 top 10 list."
Here is the history:
https://wamu.org/story/18/05/22/prince-georges-county-came-ward-9-residents-feel/
Here is the short meaning.
https://www.urbandictionary.com/define.php?term=Ward%209
Ward 9
Derogatory term for Prince George's "PG" County, Maryland, a suburb of Washington DC. Now has more murders than DC. More and more low-income African-American DC residents (and others) are being forced out of DC by high rents and real estate prices, and moving to PG County.
DC is subdivided into eight political wards. PG County is just over the border from Ward 8, which is east of the Anacostia River in DC, and DC's poorest and blackest ward.