Chief of staff for Sen. Alexander arrested over child porn charges, fired

The chief of staff for Sen. Lamar Alexander, R-Tenn., was arrested Wednesday on allegations involving child pornography.

Alexander, saying he was "stunned," fired the veteran aide, Ryan Loskarn, and replaced him before close of business Wednesday afternoon.

"The courts will judge Mr. Loskarn's guilt or innocence, but under these circumstances, he cannot continue to fulfill his duties as chief of staff of this office," Alexander said in a statement. "Therefore, as of today, I have removed him from the payroll."

Earlier in the day, Alexander revealed that agents had searched Loskarn's home. A Justice Department spokesman confirmed that Loskarn, 35, was arrested "based on probable cause for possession and distribution of child pornography charges."

"He remains in custody pending a court hearing that is expected to be scheduled for tomorrow at the federal courthouse in Washington, D.C.," the official said.

The case is being handled by the U.S. Postal Inspection Service, though other law enforcement agencies are involved. The involvement of the Postal Inspection Service indicates mail may have been used in some fashion in connection with the allegations.

Loskarn served as chief of staff for about two years, after working as staff director when Alexander led the Senate Republican Conference. He previously worked for former Sen. Jon Kyl of Arizona and other lawmakers on the House side.

Loskarn also was named one of Roll Call's "Fabulous 50" Hill staffers in 2011.

"I am stunned, surprised and disappointed by what I have learned," Alexander said in a statement. "The office is fully cooperating with the investigation."

Alexander announced that he's named his legislative director, David Cleary, as his new chief of staff.

Fox News' Shayla Bezdrob contributed to this report.