Flood, 48, was among 50 Pagans from clubs up and down the East Coast named in a racketeering indictment handed up in West Virginia last year. He was charged in a gambling scheme that was part of a broader investigation into murder conspiracy, drug dealing, and extortion.
Mondevergine was being held at the Gloucester County Jail in Woodbury pending an extradition hearing scheduled for Friday.
He was arrested at the Country Place Apartments on Fries Mill Road, where he reportedly was living with a relative, police said.
Township police officers assisted the FBI and investigators from the District Attorney's Office in making the arrest.
Mondevergine is a former Philadelphia police officer who was fired in 1982, after three years on the job, for allegedly accepting bribes to protect an illegal gambling operation. He adamantly denied the charges, which were later dropped.
In the 1990s, while working as a carpenter, the burly former South Philadelphian emerged as the leader of the Pagans. Among other things, authorities said, he formed an alliance with then-Philadelphia mob boss Joseph "Skinny Joey" Merlino.
Authorities believe the mob sometimes used the Pagans to help settle underworld disputes.
Mondevergine's status in the club faded after he was jailed on a racketeering charge in 2001. He was sentenced to 27 months in prison after admitting he had tried to gun down the leader of a South Philadelphia street gang.
Authorities believed that shooting, on Oregon Avenue about noon on Nov. 3, 2000, was in retaliation for an ambush a year earlier in which Mondevergine was nearly killed.
In August 1999, Mondevergine was shot nine times at close range as he walked home from a South Philadelphia bar. He never identified his assailants.
A year later, he opened fire on John Hendri, identified as a member of a gang that operated around 10th Street and Oregon Avenue. Mondevergine fired twice at Hendri but missed.
He was arrested with the gun in his pocket by police and FBI agents who apparently were conducting surveillance in the area that day.
Mondevergine eventually pleaded guilty to committing a violent crime in aid of racketeering, but he declined to cooperate with authorities.
In detailing those charges, federal authorities alleged that Mondevergine was part of a Pagans organization that engaged in drug dealing and loan-sharking. A dispute between the Pagans and the 10th and Oregon gang over those activities led to the shooting of Mondevergine in 1999 and his retaliation in 2000, authorities said.
The District Attorney's Office provided few details Wednesday about the shooting of Flood on Jan. 30, 2008, except to say that it "stemmed from a personal dispute within the club."
A source familiar with the case said authorities believed Flood was trying to block Mondevergine's effort to reestablish himself with the motorcycle gang.
Flood was assaulted at a Pagans clubhouse near Torresdale Avenue and Disston Street, according to authorities. He was taken to a hospital by associates, and, when first questioned by police, said he had been the victim of a drive-by shooting outside a bar.
Mondevergine, who is expected to waive extradition and be returned to Philadelphia on Friday, could face an additional charge for possessing a weapon as a convicted felon. That federal offense carries a mandatory five-year sentence.
Contact staff writer George Anastasia at 856-779-3846 or firstname.lastname@example.org.