What does one do about harassment that is not sexual in nature? My co-worker is being harassed by another co-worker. He told her that he was attracted to her and had feelings for her, would she ever leave her family, etc. She told him to knock it off, and now he sends her e-mails about putting her in a shredder, and makes comments about cutting her head off at the base, having rope and tape in his car, etc. He also prints song lyrics about violence and hands them to her. She reported him and he was written up, but she is afraid he may do something more. What should she do?

She should avoid him as much as possible.

Other than that, there is really nothing she can do until or unless he actually does do something else. The employer's only legal obligation is to make the harassing behavior stop. If he has stopped the threats, the employer's obligation has been met.

She can ASK the employer to transfer her to an area where she will not have to be in touch with him, but they are not legally obligated to do so.

CALL THE POLICE!
If this is an emergency call 911. If you let this continue your a traitor to everyone that has fought for your rights as an American citizen. If you listen to the poeple for big business and lies and tyrany America as we know will die.
I live in the safest city in the world. I am the reason. Somebody commits a crime that hurts somebody else they pay. I call the police and give them first shot at it then if that doesn't work I go to town on them. I have lived here all my life and am well known. No gangs.. no writing crap on the walls.. no street corner drug sales next to lemonade stands.. No threatning your neihboors.. It amazes me what other people are asked to put up with. I am for the common foot soldier because after all the planning and strategy the common foot soldier wins the war (wether those plans were right or wrong. ie Republicans)
What this person is doing is a crime. It is called assault. If it continues sue the owner of this company to high hell. Ask for a copy of the report your boss made. Tell your friend to make a journal of all the incidents: Time, date, place, witnesses. Tell your friend to get a small tape recorder and tape everything. When this unleashed dog starts barking turn it on and set it on your desk.
God has asked put your friend on the front line of a war that is fought accross time and place. DO NOT RUN! Animals like this person will chase you if they sense weakness. These are the people that get worse and worse and eventually shoot people at work.
Be a good American and crush this person into dust! :)