WASHINGTON » Sen. John McCain’s reaction to protesters who disrupted a hearing, calling one "low-life scum," garnered media attention Thursday, but the incident also has sparked calls for an investigation into the Capitol Police’s response to the rowdy Code Pink protesters.

"We’ve got a letter going to the police," the Arizona Republican said in the Senate subway. "And I’ve already talked to (Sen. Roy Blunt), who’s the chairman of the Rules Committee, about the sergeant-at-arms being involved. No, we’re raising hell about it."

McCain said Blunt, a Missouri Republican, is "very upset about it … (Blunt) is asking for a full investigation."

During an Armed Services hearing that featured former Secretary of State Henry Kissinger, a group of roughly 10 protesters from Code Pink, a social justice group, walked up to the witnesses, chanting, "Arrest Henry Kissinger for war crimes!"

They held signs and stood directly behind Kissinger, with one protester shaking handcuffs in front of him. They stood right behind the witnesses, chanting, for more than a minute, before eventually backing down the aisle.

McCain said he was concerned there was only one police officer on hand at the hearing. "Could I ask our Capitol Police to restore order here?" McCain asked as the protesters chanted. "Someone find out where the Capitol Police is."

Capitol Police admitted to mishandling the situation. According to a statement to CQ Roll Call provided by Lt. Kimberly Schneider, a spokeswoman for the force, "The U.S. Capitol Police (USCP) is conducting a thorough review of the events that occurred in the Senate Armed Services Committee Hearing today in room SD-G50. We take very seriously our mission to protect the Congress and its legislative processes, while balancing safety and security, and the First Amendment rights of people to peaceably assemble.

"Today, our actions in room SD-G50 clearly did not demonstrate that mission, nor did our actions meet the standards expected of the USCP.

"The USCP will continue to work with our Congressional stakeholders and the public to ensure that Congress can fulfill its constitutional responsibilities in a safe and open environment."

According to Code Pink co-founder Medea Benjamin, two of the female protesters were detained by police but were not arrested.

"The chairman had never gaveled, and so it was deemed that they weren’t going to be arrested," Benjamin said in a phone interview. "Usually the chairman would put down the gavel and say ‘arrest the protesters’ or something, and he never did that. It seems the instructions were just to clear the room of protesters and not arrest."

The incident comes two days after the Capitol Police arrested three protesters who disrupted a Senate Financial Services meeting.