The Secret Service has begun investigating comments made online by a New Jersey mother who lost her son in Iraq. The woman, Sue Niederer, first entered the spotlight last week when she was arrested after interrupting a speech by Laura Bush. At the time she was wearing a t-shirt that read “President Bush, You Killed My Son.” Earlier this year Niederer wrote an online column for the site Counterpunch where she described how she wanted to “rip the president’s head off” and “shoot him in the groined area.”