The Daily News agreed to use aliases for Oscar and his family, because they all fear retribution.
"You don't snitch, no matter what, no matter who it is or what it's about," Cheryl said. "It doesn't matter if it was the Strangler. You just don't do it."
Nine months after Oscar made that call, he was shot to death on a Kensington street corner. Court records show that Oscar, 22, had been arrested several times on drug charges, but Cheryl's not sure why he was killed or whether his tip had anything to do with it.
The District Attorney's Office did not return a request for comment.
"I don't believe he ever told anyone about making the call," she said. "It was just me and him. He would have been too scared to admit that."
The woman who witnessed Oscar's murder also broke the code. She spoke with police. She was shot to death a few months later, in daylight.
"No one on the street ever wants the police involved," Cheryl said. "They'd rather handle everything themselves."
Besides Cheryl, Oscar left behind his mother, brothers and sisters, as well as another code: a random set of letters and numbers that could mean everything to his son, Peter, who is 23 months old. It's the key to the $30,000 worth of reward money that was still owed to Oscar when he died.
"He never wanted anyone to find out that he did it, but he wanted that money for his son," Cheryl said in the living room of her rowhouse.
The Philadelphia Fraternal Order of Police paid Oscar $7,000 of reward money a few months after he supplied the tip, but for Oscar to collect the remaining $30,000 from the mayor's office and the Citizen's Crime Commission of the Delaware Valley, he'd have to wait until Rodriguez was convicted, Cheryl said.
On Aug. 16, Cheryl was on the beach in Wildwood with her mother and son when a text message alerted her of Rodriguez's conviction. She immediately called the Citizens Crime Commission and gave them the code, but says she was met with suspicion and then was referred to the Mayor's Office.
"They really just wanted to know how I got the code," Cheryl said.
She said that she told both the Citizens Crime Commission and representatives from the Mayor's Office that she'd agree to depositing the check into a trust fund or into a savings account for her son to access when he turned 18. Both Cheryl and her mother, MJ, said that no one has returned their calls.
"I think it's a disgrace," Cheryl said. "The city wonders why people don't turn people in. I just want someone to return my phone calls."
When the Daily News contacted the Citizens Crime Commission last week, its president, John Apeldorn, was unavailable, but a man who answered the phone said that the reward program wasn't "hereditary." He also said that a portion of the money was scheduled to be returned to the family of Elaine Goldberg, Rodriguez's first victim. The man at the Crime Commission would not give his name, but he said that detectives at the Police Department would have the final say over Oscar's reward.
"If the detectives make the call, we're good to go," the man said.
Mark McDonald, a spokesman for Mayor Nutter, referred all comments about Oscar's reward to the Police Department. Lt. Ray Evers said that it's going to wind up in court.
"It's going to turn out to be an estate issue," Evers said last week. "Whoever the legal heir is, the estate will get the money. We'll be more than happy to pay the reward once it's settled."
But as of Tuesday afternoon, no one from the city had contacted Cheryl or her mother to let them know any of this. Cheryl said that she and her mother have spoken with attorneys and that the lawyers told them that they wanted anywhere from $5,000 to $10,000 to take the case, and that they'd rather not go into a courtroom to hash it out.
"It really shouldn't be this difficult," MJ said. "What if he didn't call the tip in? What if a serial killer got away?"
Cheryl works full time at night as a cashier. She doesn't want to say where, afraid someone could make the connections back to Oscar.
Her rowhouse isn't far from the Betsy Ross Bridge, in a quieter, safer neighborhood than where Oscar was killed. When she spoke with the Daily News, a picture of Peter sat on a mantel inside her living room, his toys spilling out from a chest near a dining-room table.
Oscar cared for the boy during the day when Peter was an infant, Cheryl said, while she worked. The boy points to his father in pictures sometimes and Cheryl thinks that he feels Oscar's absence.
Cheryl said that the reward money won't make her son rich and certainly will never soften the lifelong loss of his father, but she'll be able to tell Peter that his father made the right choice once, and was rewarded for it.
"I deal with his loss every day," she said. "I just hope something good can come out of all this."
Contact Jason Nark at email@example.com or 215-854-5916. Follow him on Twitter @JasonNark.