WASHINGTON, D.C. -- The FBI started investigating suspicious letters today while Capitol police dealt with three suspicious packages at senate office buildings.
The packages were later deemed safe.
The investigation will focus on finding the person who sent the letters, which contained a poison known as ricin.
UNF Director of Nursing Dr. John P. McDonough says ricin is mostly used in chemical warfare... and if inhaled can be deadly
"It affects everything the body does, very dangerous substance," he said.
The FBI says the letters, dated April 8th, were postmarked from Memphis, Tenn.