Investigators picked up the suspects, who are married, at their home on Market Street near 55th, not far from where they first allegedly accosted their victim.
That woman, whom police declined to identify, has been distraught since the attack, the source said, and had trouble keeping her composure during her interview with investigators.
Lt. John Walker said the couple approached the woman just before noon on their block as she was walking to the Salvation Army on Market Street near 57th. Lorpu spoke with the victim first, and told her that she had been waiting to give her a sum of money.
"The victim realized right away that something was not right," Walker said.
After the victim balked, Lorpu walked away, but was replaced by Vickson, who spun the same tale. When the victim tried to walk away from him, he became aggressive, Walker said, and pushed her into a green Saturn sedan driven by his wife.
Inside the car, the three began to argue. After threatening the elderly woman, the couple was able to glean from her the location of the bank she uses, a Citizens Bank on Island Avenue near Lindbergh Boulevard.
There, Vickson accompanied the victim inside, and the two withdrew $8,000 from her account under the impression that the victim needed to pay for her sister's funeral.
"The victim didn't know what to do," Walker said. "She was frail, scared of being hurt."
After securing the cash, the two returned to the car, and the thieves dumped their victim on 57th Street near Market.
A police source confirmed that the two are being investigated as suspects in an incident Feb. 1 in which a man and woman abducted a 92-year-old woman on 11th Street near Chestnut in Center City and forced her to withdraw $1,200 from her account at a Sovereign Bank branch.
In that case, the thieves allegedly found their victim on the street, told her about a sum of money they were holding for her, and then forced her to direct them to her bank.
The couple - neither of whom had prior arrests - remains in police custody, the source said.
On Twitter: @Vellastrations