Charge. Arraign. Bail.

From a story in the LA Times today about a raid on a home owned by the mayor of Bell, Calif., comes this sentence:

The two men arrested, renter Carlos Zetina, 25, and his uncle Rogelio Zetina, 49, have been released on $75,000 bail but have not been charged, according to the district attorney's office.

By what process would there be bail set without a charge and arraignment? How is this possible? I look forward to the explanation.