February 5, 2016 11:55 am Authorities Work to ID Oily Substance on Potomac At least six government agencies have been working to identify the source, size and composition of an oily substance that shimmered along the Virginia side of the Potomac River. Local 1:56 3-year-old child shot in Southeast DC 26:00 DC student grazed by gunfire while in class: The News4 Rundown 2:07 Program gives returning citizens second chance — and opportunity to pay it back 2:57 Driver accused of intentionally causing fatal crash granted bond 2:11 DC police officer shoots 2 dogs to death