
MORGAN HILL, Calif. (KGO) -- Back in the United States and Santa Clara County, 20-year-old Martin Mendoza faced a judge for the first time - formally charged with the murder of his 18-year-old girlfriend Marissa DiNapoli.
DiNapoli was reported missing in Morgan Hill before her body was found days later at Anderson Reservoir.
Family and friends, including Vienna Chambers, are still reeling over a loss they feel could have been prevented.
"Two years ago, I told her he's going to kill you," Chambers said. "Two years I tried to tell her. She ended up breaking our friendship a bit because she was so in love with him and she was so sure about him, and that it wouldn't happen. And two years later, I get a call that she is missing and then found dead."
A newly-unsealed statement of facts paints a clearer picture of the alleged tragic sequence of events that led to DiNapoli's death.
Court documents say on June 29, Mendoza and DiNapoli were filmed arguing on surveillance camera at a residence on Trail Drive.
PREVIOUS: Boyfriend arrested for murder of missing Morgan Hill teen Marissa DiNapoli, police say
Phone data obtained afterwards indicates they then headed towards Anderson Lake.
District Attorney Jeff Rosen says there, Mendoza stabbed DiNapoli five times in the back and left her body near a picnic area.
"It was a lethal and brutal attack," Rosen said.
Police were called to a disturbance on June 30, the same day DiNapoli was reported missing, involving a family member of DiNapoli's and Mendoza, but Mendoza is said to have ran into the home and did not speak with police.
Morgan Hill PD told us before they did not speak to Mendoza until he was arrested.
On July 1, investigators say Mendoza fled to Mexico when his car was captured on video entering at the San Ysidro border crossing.
VIDEO: Family and friends hold vigil for Marissa DiNapoli

Days later, an arrest warrant led to his detainment by U.S. Marshals, when Rosen says Mendoza attempted to walk back into the United States.
"He left one border entrance to enter Mexico," Rosen said. "He returned a short-time later through a different entrance without a car and without a phone."
During his arraignment, Mendoza stood behind his lawyer - just out of the courtroom's view filled with family and friends of DiNapoli.
He is being held with no bail allowed and will be back for his plea hearing in September.
"Our sister deserves her justice," DiNapoli's sister Monice Ramirez said.
DiNapoli's family says they will continue to keep her memory alive, as justice is sought for someone they say brought nothing but joy to this world.
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