A woman who has a history of making threats to the U.S. Secret Service is in federal custody in Honolulu for allegedly threatening first lady Michelle Obama and for assaulting a Secret Service agent.

The Secret Service says its agents arrested Kristy Lee Roshia Saturday in Kaneohe based on a telephone call she made to its Boston field office last month threatening to kill Marines and Obama. After they arrested her, she assaulted an agent in the Honolulu field office, the service said.

The Secret Service said its Boston field office also received mail from Roshia the day before the threatening telephone call with a Kailua return address. The envelope contained photographs of Roshia, poems and love letters to a particular special agent.

When agents interviewed Roshia Saturday, she told them she knew where President Barack Obama and his wife be staying on their visit here this month and that she traveled to Hawaii in September “;to protect Obama,”; the Secret Service said.

Roshia pleaded guilty in 2007 to threatening a Secret Service special agent at the service's headquarters in the nation's capitol. A Washington, D.C., Superior Court judge sentenced her in July 2007 to 180 days in jail, followed by one year of supervised probation and two years of unsupervised probation.

The judge also ordered Roshia to undergo a mental health examination and treatment.