Travis County EMS officials hope to know sometime Sunday if the powder found in a University of Texas dorm was indeed ricin, a deadly poison.
Preliminary tests on the powder look for a protein that matches the profile of ricin.
Officials say one test returned positive for that protein, while a second was inconclusive, and a third was negative. The definitive test will come from the federal Centers for Disease Control.
The powder was found in a roll of quarters in Moore-Hill on Thursday. The quarters belonged to a student living in the dorm.
Students were evacuated from the dorm Friday night after the positive preliminary test. They were let back in after about an hour.
Travis County EMS officials say they don't think the powder was intentionally placed on campus.
"We don't think it was an intentional act where somebody would make something very fine, very aerosolized,” Commander Mike Elliot of Austin Travis EMS said. “They didn't put it by an air system. It wasn't put in a spot that one would think it was mean to harm anybody."
Authorities say no one has shown any symptoms of exposure to ricin.
UT officials are working with other agencies including the Joint Terrorism Task Force to investigate the incident.
