Officials at Georgetown University say a substance in a dorm room has tested positive for ricin.
Georgetown University Chief of Police Jay Gruber says that no one has reported any symptoms of ricin exposure since the possibility of ricin was reported on Tuesday in McCarthy Hall.
Gruber said swabs were collected from the dorm room and an analysis of those sample swabs did not show any biological threat agents.
The chief said the room was decontaminated and all areas of McCarthy Hall have reopened to students. He said there were no immediate threats to members of the Georgetown community.
According to a police report, a 19-year-old man has confirmed he made the substance. An investigation continues.