The brother of State Rep. Marguerite Quinn (R., Bucks) took a campaign sign that criticized her and supported her Democratic opponent from outside a Doylestown Borough polling place Tuesday, a poll worker said Thursday.

Sean Corr, an assistant solicitor for Bucks County and a lawyer with the Doylestown firm of Eastburn & Gray, took the sign "as evidence" and threatened to sue, Democratic committeewoman Dorothy Stratton said.

The sign criticized Quinn's support of the state's controversial natural-gas drilling law and supported Joe Frederick, her Democratic opponent. "Marguerite Quinn Fracked You. Vote for Joe Frederick," the message on the four-foot sign said.

Both Quinn and Frederick ran unopposed in Tuesday's primary and will face off in November to represent the 143d District, which covers central and upper Bucks. Quinn is seeking her fourth term.

Frederick filed a complaint with borough police Wednesday. It is under investigation, Chief Jim Donnelly said Thursday, and has been referred to the county District Attorney's Office.

District Attorney David Heckler said he and his office cannot handle the case because he has contributed to Quinn's campaign.

Returning the sign with an apology might be the appropriate response, he said.

"Prosecuting it would be kind of silly, but that's not my call," Heckler said. "If the police chief can't get it all sorted out, I'll refer it the state Attorney General's Office.'"

Corr said he had not seen the complaint and declined to comment.

The atmosphere at Salem United Church of Christ, 186 E. Court St. — the polling place for Ward 1, Precinct 2 — is normally quiet and civil, Stratton said. But things heated up about 7:30 p.m. Tuesday, after Corr arrived, she said.

Stratton had placed Frederick's sign, mounted on two wire stakes, in a grassy area near the parking lot, and it was surrounded by signs for Republican candidates.

Corr, also a Republican committeeman, asked, "Whose sign is that? Who put it there?" Stratton said. When she took responsibility, Corr responded, "You crossed the line."

Minutes later, Corr picked up the Republican signs — "that's his job," Stratton said.

"Then he yanked Joe's sign out of the ground, and I said, 'Sean, you're taking my sign.'

"Yes, I'm taking it as evidence," he answered. "I'm going to sue you" and someone else whose name Stratton couldn't make out, she said.

Corr took the sign, photographed it, and returned it to police, Quinn campaign spokesman Jason Ercole said.

"The representative was not involved," Ercole said. "And the signs were as vulgar as you can get. They were thinly veiled references against the representative."

Frederick acknowledged that the sign was controversial.

"It was meant to be that way," he said. " We were upset with what she [Quinn] did in Harrisburg. Our rights were given away to the gas and oil people without any thoughts to us."

Quinn supported Act 13, which charges fees for drilling in the Marcellus Shale. The law has drawn heated opposition for provisions that supersede local zoning laws that restrict drilling.

Contact Bill Reed at 215-801-2964 or wreed@philly.com, or follow on Twitter @breedbucks. Read his blog, "BucksInq," at www.philly.com/bucksinq.