KNOXVILLE, Tenn. (AP) -- A former Knoxville police officer has been charged in what investigators say was an online threat to a prosecutor.

Donald Scott Clark was arrested at his Maynardville home Friday and charged with retaliation for past action, which The Associated Press describes as a seldom-used statute that makes it illegal to threaten a witness or court official in a judicial case.

Clark earlier lost his police job when he pleaded guilty to offering teenage girls alcohol. He posted messages on Facebook that authorities saw as threatening the life of Assistant District Attorney General Steve Sword.

The prosecutor said he couldn't discuss the arrest.

Clark is free on $5,000 bond. His lawyer says the posting was the ramblings of his client who has been using a prescription sleep aid.

------

(Copyright 2011 by The Associated Press. All Rights Reserved.)