On Thursday, the parents of the missing 27-year-old Oakley woman received copies of notes investigators say were handwritten by Gabe's ex-boyfriend Marshall Curtis Jones. According to a letter from police, Jones wrote directions in the notes on where to dispose of Alexis's body in Pioneer, which is an area 60 miles east of Sacramento.
RELATED: Oakley woman's disappearance now homicide investigation, police say
In the note, investigators say Marshall turned off his phone for several hours while driving to Pioneer, but were able to pinpoint his location when the phone turned on.
"His phone was there," said Gwyn Gabe, Alexis's father. "It pinged around that area... we thought it was something to throw police off."
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Jones was killed last month during an arrest attempt near Seattle after allegedly charging at officers with a knife inside an apartment complex. According to the note, after Jones' died, a friend came forward stating Jones called him two weeks before Gabe disappeared. The note says Jones told the friend he was "thinking about killing Alexis and wanted to know where the best place to hide a body would be."
VIDEO: Family of missing Oakley woman Alexis Gabe speaks after suspect killed by police
Family of missing Oakley woman Alexis Gabe speaks after suspect killed by police
The cryptic directions in the notes were specific - detailing left and right turns with specific time estimates that ended on a rural road in the Sierra foothills up in Amador County.
"As soon as police saw that - they left and went straight to Pioneer," said Gabe.
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Investigators mention in the note that Marshall and the friend decided "the best place to dispose of a body would be by placing it in a septic tank or burying the body in a forest area."
According to Gabe, investigators and hundreds of volunteers searched nearly 200 acres of land in Pioneer over the past four months for any sign of Alexis's body - including draining more than eight million gallons of water in a nearby pond.
"Unfortunately, they found nothing," said Gabe.
RELATED: Parents of missing Oakley woman believe she is still alive as new developments unfold
The family says they were escorted by investigators up to Pioneer this week to visit the search area.
"They're only focusing on Pioneer," said Gabe. "They strongly believe she is there."
"Do you believe that too?" ABC7's Stephanie Sierra asked.
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"Not 100 percent," said Gabe. "I don't think Alexis is there... my wife strongly believes she's still out there. That she's still alive."
The Gabe's believe Alexis is closer - somewhere within the Bay Area.
"Until we find a body," said Gabe. "We're just going to keep believing that she's still alive."
VIDEO: Investigators find cellphone case belonging to missing Oakley woman
Investigators find missing Oakley woman's cellphone case
In the meantime, the Gabe family is focusing their attention on another piece of evidence recovered from investigators - Alexis's cellphone screen. According to Gabe, the FBI confirmed Marshall Jones' DNA was discovered on it and they hope to recover the rest of the phone with the help of another search with volunteers.
If you have any information that could help investigators, call the Alexis Gabe tip line at 925-625-7009.