Janet Napolitano endorsed Barack Obama in January 2008
Arizona Governor Janet Napolitano has been picked to head the Department of Homeland Security in President-elect Barack Obama's incoming administration.
President George W Bush created the department after the 11 September attacks.
Ms Napolitano was elected governor of Arizona in 2002 and re-elected in 2006.
She quickly became one of America's most respected public officials: in 2005, Time magazine called her "a mountaineer on the political rise" and listed her as one of America's five best governors.
As governor of a state bordering Mexico, Ms Napolitano has been an important voice on immigration issues.
In 2005, she became the National Governor Association's first female vice-chair and then became its first female chair in 2006.
Ms Napolitano served one term as Arizona's first female Attorney-General.
In 1993, President Bill Clinton appointed her US Attorney for the District of Arizona.
She graduated from Santa Clara University and received her law degree from the University of Virginia. She moved to the state of Arizona in 1983.
Ms Napolitano was an early supporter of Mr Obama, endorsing him during the January 2008 primaries.