The cocaine was so pure that the amount in each card was valued at $4,000, Werner said.
After finding substitute cards, gluing the Peruvian stamps to the new envelopes, and obtaining search warrants, Officers Tim Bogan and Gina Jackson set off to the deliver them.
Masquerading as a neighbor who had received the card accidentally, Jackson took it to a house on the 900 block of Atwood Road in the Overbrook section, Werner said.
After Jack Ferguson, 45, accepted the card, he was arrested and charged with possession with intent to distribute narcotics, police said.
When no one answered at the other addresses, police obtained new search warrants and arrested Thursa Dennis, 62, at her home on the 6100 block of North Marshall Street in Olney, Werner said.
He said Dennis' son, Grady Dennis, 41, and his wife, Yolanda Dennis, live in the third house to which a card was sent, on the 8600 block of Michener Avenue in Ivy Hill, but they were in Florida when police made their move.
The cash, weapons and other drugs were found at the two Dennis households, Werner said.
The Dennises were supposed to return yesterday but did not. Werner said warrants were being sought for their arrest.
Contact staff writer Joseph Gambardello at 215-854-2153 or jgambardello@phillynews.com.