Justice Served Act of 2018 This bill amends the DNA Analysis Backlog Elimination Act of 2000 to add, as a purpose area under the Debbie Smith DNA Backlog Grant Program, increasing the capacity of prosecutors to address the backlog of violent crime cases involving suspects identified through DNA evidence. The Department of Justice (DOJ) must allocate a specified percentage of grant funds for such purpose, subject to limitations. Additionally, of amounts made available over FY2019-FY2022 for a DNA analysis and capacity enhancement program and for other forensic activities, DOJ must allocate at least 5% for grants to prosecute cold cases involving violent crime, where suspects have been identified through DNA evidence.