The chief of staff for Tennessee Republican Lamar Alexander was arrested this afternoon by the U.S. Postal Inspection Service based on probable cause for possession and distribution of child pornography charges. He has been put on leave without pay, Sen. Alexander’s office announced on Wednesday. According to the statement, law enforcement agents searched the home of Ryan Loskarn, hired by Alexander in 2011. “I am stunned, surprised, and disappointed by what I have learned,” Alexander (pictured at left) said in the statement. Alexander’s office said it is “cooperating fully” with the investigation. Loskarn is in custody pending a hearing tomorrow.