The FBI investigates a Fannin County man after he shows up at the hospital and admits he's been exposed to deadly ricin.

The Atlanta Journal-Constitution reports William Christopher Gibbs is now in local custody, charged with reckless conduct and violating probation.

The Fannin County sheriff says Gibbs' vehicle tested positive for a small amount of ricin.  He'd apparently tried to make it himself from castor beans.

On Facebook, Gibbs identifies as a "white racial loyalist."  His mother acknowledges his involvement with white supremacists but denies he intended to harm anyone.

Tammy Gibbs characterizes her 27-year-old son's troubles with the law as "general stupidity" but insists he is not violent.

She claims he is bi-polar and schizophrenic.  "He doesn't think like you and me," she tells the AJC.

U.S. Attorney John Horn confirms Gibbs is under federal investigation.  He says there is no evidence the public is at risk.

In 2011, four men in north Georgia were arrested for allegedly plotting to use ricin in domestic terror attacks.  Two men pleaded guilty and the other two were convicted at trial.