Agreed, definitely needs a source, as well as a minimum limit for population. If you're including smaller towns, there are a lot of smaller towns (e.g. Camden, NJ; Chester, PA; etc.) that have really high crime rates too. Although most lists I've seen stick just to major cities (which would leave out Flint, Gary, Compton, and Canton from your list). Secondly, I've never seen a list that has Philadelphia higher than Baltimore. In fact, Philadelphia's crime rate is generally in the 20-25th range for major U.S. cities (and New York and Washington well below that). Other cities that seem to be missing are New Orleans, Memphis, Milwaukee, and Albuquerque (all four are in the top 10 for per capita violent crime rates).