Holder Threatens to Sue Arpaio

The Justice Department says an Arizona sheriff known for his efforts against illegal immigrants has refused to cooperate with a civil rights investigation and the department is threatening to sue.

Since March 2009, the U.S. Justice Department has been investigating Maricopa County Sheriff Joe Arpaio's office in Phoenix for alleged discrimination and for unconstitutional searches and seizures. Arpaio says the inquiry is focused on his immigration efforts.

In a letter, assistant attorney general Thomas Perez gives the sheriff's office until Aug. 17 to turn over documents first requested last year in what the department calls an inquiry into claims of discrimination based on national origin.