By Maria Medina

SAN JOSE (CBS SF) — A South Bay man who is accused of trying to kill his ex-girlfriend then kidnapping their daughter is now behind bars after good Samaritans recognized him from an Amber Alert.

Cell phone video recorded by witness Tammy Hall shows at least three men surrounding 24-year-old Victor Magana in Cambria Monday afternoon. Magana tries to smash his car window with a rock after locking his keys and daughter in the car. The good Samaritans stop Magana as Hall continues to record the scene on her phone.

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Magana is seen trying to convince the men that he’s just trying to feed his daughter. He denies that he is the suspect in the Amber Alert despite the fact that his car matches the Green Hyundai SantaFe with a California license plate of 7XJX025 in the alert. One good Samaritan even blocks Magana’s car with his own car to stop him from leaving.

Hall said one of the men eventually put Magana in a chokehold before he bear hugged him until officers arrived and took him into custody.

Magana’s 2-year-old daughter, who he is accused of abducting, was found unharmed in the front seat of the car.

About twelve hours before Magana was arrested, officers said he attempted to murder his ex-girlfriend at a home on the 500 block of 11th Street in downtown San Jose.

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Police responded to a call of a woman screaming at 10:04 p.m. and discovered the victim unconscious with at least one stab wound.

“There’s a cord around her neck, it’s going to be an appliance cord,” a dispatcher is heard saying in scanner traffic from the call.

“She’s got a laceration to her neck from the cord,” said an officer on scene. “Possibly life threatening…she’s got a cut from ear to ear across her throat.”

The victim, whose identity has not been released, is in critical but stable condition.

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A source told KPIX that the victim and Magana has a history of domestic violence, but were not together.