The investigation that followed involved officials from two states and the FBI, but no one has been able to answer the question of what happened to the New Jersey couple.
Now on this somber anniversary, investigators are once again asking the public for their help in solving the case.
Cold Case Blog: The Missing South Street Couple
Imbo, 34, and Petrone, 35, had been dating for about a year when they went to Abiline, a now defunct bar and restaurant along South Street in Philadelphia on February 19, 2005. It would be the last time anyone saw them.
“They weren’t using bank accounts, cell phones, nothing. It’s hard in this day and age to disappear like that, so we have every reason to believe that foul play is involved,” FBI special agent J.J. Klaver told NBC10’s Mike Strug Wednesday.
Family and investigators describe the couple as stable. Both have children from previous relationships and held good jobs.
Officials believe the two may have been the victims of a murder-for-hire plot, but will not say why.
The couple has been pronounced dead, but the investigation still remains active.
“When it comes to murder, we don’t give up,” Klaver said.
Petrone’s Dodge Dakota pickup truck was also never found.
A $50,000 reward is being offered for information leading to the whereabouts of the couple. Anyone with information is asked to call either the FBI at 215-418-4000 or the Citizens Crime Commission tipline at 877-345-TIPS or 215-546-TIPS. Tipsters can remain anonymous.