A St. Paul woman was saved from an hourslong knife attack by her boyfriend when she sent a selfie of the alleged assault to his brother, who contacted her on Facebook video messenger and called police.

The woman’s boyfriend, Peter Vang, held her down and pressed a gun-shaped knife with a 3-inch blade to her neck for six hours until the brother, who lives in Milwaukee, Wis. watched a live feed of the incident over Facebook messenger and called police, according to court documents.

The brother’s call was prompted by a selfie that the woman “surreptitiously” took and sent to him.

“She was able to take a selfie photo and communicate that to the defendant’s brother, who in turn called to find out what was going on and attempted to intervene,” said Ramsey County attorney spokesman Dennis Gerhardstein.

Vang, 33, of St. Paul, was charged Tuesday in Ramsey County District Court with second-degree assault and domestic assault for the incident Saturday at the woman’s apartment.

The woman suffered several red scratches and marks on her neck, and told police that Vang, who laughed throughout the ordeal, was possibly high on meth and that she feared he would have injured or killed her.

According to the complaint: Vang’s brother and sister-in-law called St. Paul police about 10 a.m. Saturday to report the alleged assault the brother witnessed. He also told police that Vang has a history of violence and methamphetamine use.

Vang answered the door when police arrived at the woman’s St. Paul apartment.

“Police noted [the woman] appeared very distraught,” the charges said. “They saw her arms and hands shaking. Police saw numerous horizontal red marks and lines across the front of her neck.”

The woman told police that she had been dating Vang for about six months, and that he had been acting paranoid and thought that someone else was inside the apartment.

Vang called police three times around 3 a.m. Saturday due to his paranoia, she told police, who had responded to at least one of the calls.

The woman told police that she fell asleep on the floor, and woke up between 4 a.m. and 4:30 a.m. to Vang holding her from behind in a bear hug. Vang allegedly pulled out a knife and pressed it against her neck for hours.

“During those hours,” the charges said, “Vang kept asking her why she let the “people” inside her apartment.”

The woman took a selfie of the alleged assault. The brother contacted the woman via Facebook messenger and begged for Vang to put down the knife. When Vang refused, the brother called 911.

Police found the suspected knife and a bag of suspected meth at the scene, along with $865 in cash in Vang’s wallet.

Vang allegedly told police that the drugs belonged to him and that he put the knife to the woman’s throat to protect her against “ ‘gang bangers’ ” who were looking for him, the charges said.

Vang has three prior domestic violence-related convictions.

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