The mother of the 27-year-old Democratic National Committee staffer shot and killed in his D.C. neighborhood last month is asking the public for help solving her son's murder.

Mary Rich, the mother of Seth Conrad Rich, spoke Thursday afternoon on the block in the Bloomingdale neighborhood where her son was killed July 10.

She and D.C. police chief Cathy Lanier asked anyone with information on the unsolved killing to come forward.

Rich was shot multiple times on the 2100 block of Flagler Place NW.

It is possible he was killed in an attempted robbery, Lanier said. The case remains under investigation.

Rich, a Nebraska native, was a rising star in the DNC, colleagues said.

Mary Rich said she took comfort in knowing her son tried to make the world better.

"The only thing I can say as a mother is it warms my heart that he lived such a great life, even though it was cut short," she said. "I can always hold on to that."

Anyone with information on the shooting is asked to call police at 202-727-9099 or send a text message to 50411. A reward of as much as $25,000 is offered.

Stay with News4 for more details on this developing story.