Sister Perreca, an eighth-grade teacher at St. Martin of Tours School in Oxford Circle, was hit around 6:30 a.m. on Jan. 9, 2006, near Hawthorne and Cottman avenues as she walked to St. Matthew's Church. The driver never stopped.
"I cannot believe it's been 20 years. And nothing. Nothing," said Sue Lavin, who still works at St. Martin of Tours and recalls the shock that spread through the school community. "It was devastating. We were just, as a community, we were crippled."
Lavin said Sister Mercedes Perreca was deeply involved in school activities and always brought joy to community events.
"She meant a lot. She was involved in everything. If we had a bingo or an Oktoberfest, she would be sure to be there with one of her many caps on her head. Dancing, singing, getting the kids to join in," she said.
Investigators believe the vehicle that killed Sister Mercedes Perreca was a two-tone red 1987-89 Ford F-150 pickup with "FORD" embossed on the tailgate.
"It's 20 years old, but you don't forget things like that," said John Appledorn of the Citizens Crime Commission. Calling the act "coldblooded," he added, "Somebody should be made to pay for that."
Appledorn said cases like this often hinge on people who saw something but were afraid to speak up at the time.
"What you have sometimes is people seeing something and don't want to come forward originally. And it's preying on their mind all those years, and they see something like this and come forward," he said.
Lavin hopes that anyone who knows what happened will finally reach out.
"I don't think anybody intentionally meant to hurt her. But it's been 20 years, it's time to set your heart free and do the right thing," she said.
Police and the Citizens Crime Commission are urging anyone with information about the truck or the driver to contact authorities.