But the incident has raised the question of whether the House's security staff had sufficient policies in place for screening and background checks - and whether they should have been armed in the first place.
Security guards for the Senate do not carry weapons, and the Capitol complex is already protected by the Capitol Police, an accredited force whose officers receive extensive training in firearms, emergency management, hazardous materials, and riot control.
"We are the first line of defense," said Dave DeLellis, president of the Fraternal Order of Police Lodge 85, which represents Capitol police officers and which has raised concerns about House guards carrying weapons.
"That is part of the core function we provide in the Capitol, and we consider ourselves to be the best at it," DeLellis said.
The House's legislative security guards are supposed to protect people and property in the rooms and other spaces occupied by the chamber, according to an official description of the job. They also investigate complaints, accidents, and suspicious people or behavior. Salaries for uniformed officers range from $23,000 to $41,200.
In January 2006, House leaders armed the guards with .357-caliber handguns. The decision was made by the House's five-member Bipartisan Management Committee, made up of legislative leaders from both parties. At the time, that included Republican House Speaker John M. Perzel and Democratic House leaders Bill DeWeese and Mike Veon. All three have since been convicted on political corruption charges.
The move was controversial. Coming just after the legislature had passed the hugely unpopular legislative pay raise, it was disparaged as evidence that lawmakers were frightened of the public outrage over the pay raise.
Defenders said the guards needed to be armed to protect against terrorism and prevent incidents such as the July 1998 shootings at the U.S. Capitol that killed two security guards.
In an interview last week, the former director of security for the legislative officers, Phil Frederick, said he advocated arming the guards for years. When the decision was made to do so, Frederick said, his officers received rigorous training in a special program through Temple University.
Frederick was among the three people who resigned in May after it was discovered that one of the House guards, Brian Marhon, had a criminal background.
Marhon, hired as a House security officer in 2001, could not be reached for comment.
Court records show he faced simple-assault assault charges in 1994, to which he pleaded guilty; DUI charges in 2003 and 2004, to which he also pleaded guilty; and aggravated-assault, simple-assault, and harassment charges in 2008, after which he pleaded guilty to simple assault and harassment. In all cases, records show, he received probation.
Frederick called Marhon "an exemplary employee."
Frederick said he was aware of Marhon's 1994 incident and the DUI charges, but said they were misdemeanors and did not disqualify him from the job. Frederick said he thought Marhon's 2004 charges were related to a civil issue.
He said that starting in 2006, all uniformed House officers underwent fingerprint and FBI background checks. Before that, guards underwent a state criminal background check, psychological testing, drug testing, and a physical examination.
There were no periodic follow-up checks. Not until 2009 was a policy put into place that guards report any run-ins with the law, Frederick said.
Top House leaders and officials, including Chief Clerk Anthony Barbush, became aware of Marhon's background in late April, according to two sources who asked not to be identified. Those sources said Barbush immediately ordered that Marhon be terminated.
Frederick confirmed that he had a series of tense meetings with Barbush after Marhon's record became known. He said he recommended temporarily disarming the security guards.
But he said Barbush told him he no longer had confidence in him, so he submitted his resignation.
After he resigned, Frederick said, two other House security officers, both supervisors, were asked to submit their resignations.
"I have no regrets," said Frederick, who worked at the Capitol for 13 years. "These officers are dedicated people. And make no mistake about it: Every one of them would go the extra mile."
Contact Angela Couloumbis
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Inquirer staff writer Michael Macagnone contributed to