By Jay Gormley, CBS 11 News

DALLAS (CBSDFW.COM) – It’s been nearly a year and a dear friend of three Dallas women is still missing.

Tina Wiley, Joni Shannon and Tammye Markle have taken 52-year-old Lisa Stone’s case into their own hands.

Stone was last seen on June 5, 2010 at her far east Dallas home where she lived with her life partner.

“She did not have a mean bone in her body. She was always good to me,” remembered friend, Joni Shannon.

“I just felt something had to be done,” said Wiley. “When doors were slammed in my face by the authorities and other people, that just made me want to try harder.”

The women have set up a Facebook page, put up billboards and held vigils in hopes of finding Stone. The three friends have been close to Stone ever since their days at mesquite high school in the mid 1970s.

Police have identified Stone’s partner Sherry Henry as a person of interest. Stone’s three friends are convinced Henry knows something.

“How does someone going missing who you’ve lived with for 16 years and you don’t have any clue,” asked Wiley.

For the first time, Henry is talking publicly and is lashing out at her accusers.

“You will not tear down my life. You will not point the finger at me, until you have verifiable proof that I have ever done anything other than support Lisa Stone in whatever she wanted to accomplish in her life,” said an emotional Henry. “Lisa and I love each other. End of discussion!”

Stone’s three friends continue to follow tips left on Facebook and have even searched creeks and dumpsters in East Dallas.

The CBS news magazine 48 Hours will dedicate an entire hour this Saturday night to the disappearance of Lisa Stone.  The program will run at at 9:00 on CBS 11.