Homeland Security Secretary Janet Napolitano said Wednesday that a former Secret Service agent's Facebook post in which he claimed to be ogling Sarah Palin was "unacceptable and unprofessional."

The posting came to light after the agent, supervisor David Chaney, was forced to resign following the prostitution scandal in Colombia. In a photo showing him looking at the then-GOP vice presidential nominee, Chaney wrote that he was "really checking her out."

Napolitano discussed the agent and other aspects of the prostitution scandal during testimony Wednesday before a Senate committee on Capitol Hill. She said she had no knowledge of any similar incident over the past two-and-a-half years, and that the alleged April 11-12 incident posed "no risk" to President Obama, who arrived later for the Summit of the Americas.