Elizabeth Holmes' Life Before Prison Detailed in Partner Billy Evans' Letter To Judge

Elizabeth Holmes' life before prison was apparently filled with more drama than anyone knew ... including a deadly mountain lion attack, a six-month escape from the spotlight and a desperate plea to keep her out of prison ... TMZ has learned.

With the disgraced Theranos founder back in the spotlight thanks to the new documentary "You Can See Everything," TMZ has obtained a 2022 letter her longtime partner, Billy Evans, wrote to the judge who would go on to sentence her ... offering a wild glimpse into their lives as her fraud case unfolded.

In the letter, Evans paints a very different picture of the convicted fraudster ... describing her as loving, selfless and even naive ... with him affectionately referring to her as "Liz" throughout.

Evans says the two met at a charity event in 2017 and immediately hit it off ... though they remained friends for six months before things turned romantic, with Billy initially hesitant because of the negative headlines surrounding her.

One particularly heartbreaking story involved their Husky, Balto ... who Evans says was snatched from their front porch by a mountain lion.

He claims Holmes spent 16 hours searching through brush and poison oak, refusing to give up hope until she found the dog's lifeless body.

And that wasn't the only ordeal Evans recalled ... claiming Holmes continued working for a crisis hotline while battling COVID-19 and a 104-degree fever during her pregnancy, even taking calls from her hospital bed.

The letter also detailed the couple's extreme efforts to escape the media circus surrounding the Theranos scandal.

Evans claims the attention became so overwhelming that they spent six months traveling through national parks in a truck ... sleeping at campgrounds and Walmart parking lots to get away from the cameras.

He also accused a CNBC reporter of sneaking into their apartment building, posing as a resident and exposing their address ... claiming the incident contributed to their decision to leave.

Evans also insisted Holmes was so trusting that people would befriend her just to take advantage of her connections ... claiming she was completely oblivious to their intentions.

But the most emotional part of his plea centered on their growing family ... at the time, Holmes was pregnant with their second child, and Evans feared their young son would grow up visiting his mother behind prison glass.

He described Holmes singing "Amazing Grace" to their son at bedtime ... begging Judge Edward J. Davila to consider the woman he knew rather than the disgraced entrepreneur portrayed in the headlines.

His final request was simple ... "Please let her be free."

Of course, that didn't happen ... Holmes was sentenced to more than 11 years behind bars for defrauding Theranos investors.

Billy's family also rallied behind Holmes ... with his father, Bill Evans, calling her "kind and nonjudgmental," while his younger sister, Grace, credited Holmes with helping her escape an abusive relationship and cope with panic attacks.

Now, Holmes' story is getting renewed attention through the documentary, which follows Holmes and her family in the weeks leading up to her imprisonment in 2023.