This story was reported by Christopher Ruvo & Peter Hall of the Intelligencer and by Daily News staffers Dana DiFilippo and Albert Stumm.

Authorities say he was the mastermind behind a million-dollar illegal prescription-drug operation.

He was accused of attempted murder for beating a man to a pulp over a drug debt, and rumors circulated that he was involved in the disappearance of a South Jersey couple from South Street five years ago.

But Robert Carey will never face the music.

Carey, 40, of Palmyra, N.J., hanged himself with a shoelace in his Bucks County Jail cell on Wednesday, officials said.

Carey had been incarcerated Tuesday after being arraigned on charges that he ran a drug operation that, authorities said, illegally sold prescription painkillers in Bucks, Montgomery and Philadelphia counties for a decade or more.

Carey, who court records say once boasted to his girlfriend that he had "tight friends strictly from fear alone," was found on the floor of his cell at 9:59 p.m. with a shoelace around his neck, Bucks County District Attorney David Heckler said.

Carey was facing felony identity theft charges for allegedly forging prescriptions for at least 142,428 tablets of OxyContin and Percocet between January 2008 and February 2010, records said.

Philadelphia authorities had already charged Carey in March with attempted murder for allegedly beating a man so severely that the man lost an eye.

The victim owed a $2,400 drug debt to Carey, who stalked the victim and caught up to him on Jan. 8, beating him at a Philadelphia warehouse, court records said. The victim lost his left eye and suffered a concussion, said authorities. His nose was broken and he had three fractured bones over the top of his left eye.

An agent from the Attorney General's Office testified that Carey attempted to coerce a man who works with the victim into testifying that the victim's attacker wore a ski mask.

When South Jersey couple Danielle Imbo and Richard Petrone vanished from South Street in February 2005, rumors circulated that Carey was the hit man who made them disappear.

A law-enforcement source said authorities eyed Carey but never declared him a suspect. And a source familiar with the Port Richmond area in which Carey ran part of the drug operation said that street talk had implicated Carey in the couple's disappearance.

Yesterday, FBI Special Agent J.J. Klaver said investigators don't have any suspects in the case, despite a $50,000 reward.

Still, he acknowledged, many investigators believe a murder-for-hire motive led to the couple's disappearance. On Feb. 19, 2005, Petrone, 35, and Imbo, 34, were having drinks with another couple at a South Street bar and left together shortly before midnight in Petrone's black 2001 Dodge Dakota pickup.

No one has seen or heard from them since. The truck was never found and their credit cards, bank accounts and cell phones were never used again.