(Image Credit: SAUL LOEB/AFP/Getty Images)

The actions of the "knuckleheads" accused of misconduct in the Secret Service scandal should not diminish the importance of the agency's work, President Obama said today.

"The Secret Service, these guys are incredible," the president told NBC's Jimmy Fallon, according to press pool reports. "They protect me, they protect our girls. A couple of knuckleheads shouldn't detract from what they do."

"What they were thinking, I don't know," Obama said. "That's why they're not there anymore."

A dozen Secret Service officials are being investigated for misconduct, including excessive drinking and cavorting with prostitutes, ahead of President Obama's trip to Cartagena, Colombia earlier this month. Six Secret Service personnel have since left the agency in the wake of the controversy.

The president's interview, taped in Chapel Hill, N.C., this afternoon will air in full tonight on "Late Night with Jimmy Fallon."