Tomorrow will mark the 4-year anniversary of the mysterious disappearance of Danielle Imbo and Richard Petrone Jr. The couple vanished after they left Abilene's, a bar and restaurant on South Street near 5th. They were supposed to be driving Petrone's 2001 Dodge Dakota back to Imbo's Mount Laurel, N.J., home, but police said they never made it. Petrone's truck was never found. The couple's bank accounts and credit cards were never accessed, either.

Last year, FBI officials acknowledged their investigators believed the couple were the victims of a murder-for-hire plot. The announcement was music to the ears of Petrone's family.  "The FBI never discovered anything in either one of their backgrounds that would have led to this," Petrone's father, Richard Sr., told the

Daily News

last year. "We felt all along that someone took them against their will, but that it was not a random criminal.

FBI officials earlier today issued a reminder about a $50,000 reward posted by the Citizens Crime Commission of Delaware Valley for information that simply leads to the couple's whereabouts. Tipsters can call 215-547-TIPS.