A good Samaritan found her cellphone nearby about three hours after she went missing. Police found the other one in Richmond. Now they're looking at the Ivy League graduate's background and the months that led up to her disappearance.
"This is completely uncharacteristic of my sister to disappear," Sandra's sister Tanya Coke said.
Tanya says her 50-year-old sister, Sandra, works with death row inmates as an investigator with the federal public defender office.
Police aren't sure if Sandra's disappearance on Sunday night, is related to her job or a meeting with someone who had information about her missing dog.
"She told her daughter she would be home in half an hour and was not seen thereafter," Tanya said.
The story goes back to last May, when Sandra's King Charles spaniel, named Ginny, was stolen from their home in Oakland during a burglary. Then a stranger called.
"And said, 'I have information about your dog. How much is your dog worth to you?' And she still got nothing," Tanya said.
Police won't confirm the extortion plot, but Tuesday they discovered Sandra's Mini Cooper in a parking lot not far from their home.
The night she disappeared, Sandra's 15-year-old daughter tracked her mother's work cellphone.
"A good girl, a resourceful girl; she was using the Find My iPhone app and was able to tell the police where the phone was," Tanya said.
Police found one phone near the McDonald Street exit in Richmond. The other near Emeryville and north Oakland.
Coke is described as black, 5 feet 6 inches tall and 150 pounds, with a medium complexion, brown hair and brown eyes. She was wearing a black-and-white shirt and dark jeans when she disappeared.
Anyone who may have seen Coke is asked to call the Oakland Police Department's missing persons unit at (510)-238-3641, Crime Stoppers of Oakland at (510)-777-8672, tip line at (510)-777-2805, toll-free tip hotline at (855)-TIPS-247, family and friends tip line at (415)-385-5190, or email tips to Findsandracoke@gmail.com.
Bay City News contributed to this report.