HARRISBURG – Rob McCord, the former state treasurer who once dreamed of being governor, returned to the state capital Wednesday as a convict and government witness, telling jurors how he got caught extorting campaign donors and began helping the FBI build a case against a Chester County businessman.

"It was stupid and wrong, and I take responsibility," McCord said. "It was an abuse of the office and I take responsibility -- and I regret it."

His comments began what is expected to be several days of testimony at the trial of Richard Ireland, accused of trying to bribe him in return for state contracts.

For McCord, who won two statewide elections as treasurer, it was his first return to the spotlight after an abrupt downfall and nearly two years of silence. What he reveals could send ripples through the state's political and governmental circles.

A longtime Democrat from Lower Merion, McCord agreed to become a secret FBI cooperator after being caught on a federal wiretap attempting to shake down contributors during his unsuccessful 2014 campaign for governor. He resigned from office in late January 2015, pleaded guilty to extortion weeks later, and essentially vanished from view. He awaits sentencing.

One contributor McCord targeted was William Sasso, chairman of the Philadelphia-based law firm Stradley Ronon, he testified Wednesday. In a February 2015 interview, Sasso denied that his firm had been targeted by McCord for a shakedown.  Efforts to reach him Tuesday night were unsuccessful.

Now 58, his once-dark hair turned a stark white, McCord sat quietly late Wednesday afternoon on a hallway bench outside the courtroom, reading a John Sandford crime novel, until called to the stand.

He testified for barely an hour, answering routine questions from one of the prosecutors, Michael Consiglio, and helping to explain as jurors listened to secret FBI recordings of three of his conversations with Ireland.

Ireland, 80, is charged with seeking to privately funnel to McCord more than $500,000 in campaign donations through business associates. Prosecutors allege he promised McCord a high-finance job once the treasurer returned to the private sector. The trial, before a jury of seven women and five men, opened last week in the courtroom of U.S. District Judge John E. Jones III.

For years a major political donor, Ireland worked as a "fixer" of sorts, helping financial firms gain access to contracts for managing public money and getting a share of those deals. Between 2001 and 2010, Ireland's firm collected millions of dollars in fees from the deals, prosecutors said during opening statements last week.

Ireland's lawyer, Reid H. Weingarten, has countered that there was never a quid pro quo in his client's dealings with McCord.

During his testimony Wednesday, McCord told jurors Ireland had been his friend. In the tapes played for jurors, he often referred to Ireland as "a partner." In seeking campaign donations, McCord suggested Ireland would get a return on his investment -- even if McCord didn't become governor and remained treasurer. FBI agents made those recordings before McCord became a government witness.

"You know we are a team," the treasurer told Ireland in one April 2014 phone call recorded by agents. In another call monitored that month, Ireland told McCord: "I'm there for you. You know that."

When McCord returns to the stand Thursday, jurors could hear more about when and how he was confronted by authorities, the terms of his cooperation, and how long he agreed to let agents secretly record his conversations.

What follows could be a potentially tense cross-examination. Weingarten has painted McCord as calculating and manipulative, someone who will say anything to save himself. In this case, the defense lawyer has said McCord was trying to spare himself from a devastating criminal corruption case.