Just when Jocelyn Kirsch and Edward Anderton thought it was safe to exhale . . .

Law-enforcement sources said yesterday that the FBI, the U.S. Attorney's Office and the U.S. Postal Inspection Service have all launched separate investigations into the busted, so-called "Bonnie and Clyde" couple.

The new investigations - and the specter of possibly having to face stiffer federal charges - come at a time when the spirits of the formerly glamorous duo are likely at an all-time low.

Anderton, 25, and Kirsch, 22, were arrested Nov. 30 on charges that include burglary, criminal trespass and conspiracy.

They were arraigned on Thursday and sprung from fetid jail cells after their parents came to their rescue and posted 10 percent of their combined $235,000 bail.

Anderton returned to his family's home in Washington state, while Kirsch headed south to her father's home in North Carolina.

Police said the photogenic couple funded lavish vacations and expensive shopping sprees by stealing the identities of well-heeled neighbors in their Center City condo.

If Anderton and Kirsch end up facing federal charges that could include identity theft and mail fraud, the district attorney's office would likely drop its charges against them, police officials said.

After the couple's arraignment Thursday, Kirsch's attorney, Ron Greenblatt, described them as "sad and scared."

Victims and former friends came out of the woodwork throughout the week as the stunning story of the alleged identity-stealing duo made headlines around the world.

Kirsch's surgically enhanced bust and her outrageous claims - including that she was an Olympic pole-vaulter - were of particular interest on Web sites and blogs, including Facebook, which devoted whole pages to the topic.

Anderton, a University of Pennsylvania graduate, is the topic of conversation in his native Snohomish, Wash., according to old friends.

"He was a really nice guy, really driven, a really hard worker," Erica Chandler, a former high-school classmate, said yesterday. "I'm completely shocked by this entire situation."

Kirsch, who was in her final year at Drexel University where she was studying business, has been suspended from the school, Greenblatt said.

Kirsch was arrested in November 2005 and charged with retail theft at the Lord & Taylor in the King of Prussia Mall, according to Montgomery County records. She pleaded guilty and paid fines and court costs totaling $268.50.

Two other unrelated shoplifting cases against her in Philadelphia were dismissed, Greenblatt added. Assistant District Attorney Mark Winter, of the D.A.'s economic and cyber-crime unit, declined to comment yesterday *