FRESNO, Calif. (KFSN) -- Cell phone video captured the aftermath of the stabbing that killed 20-year-old Isaiah Casillas in August 2019.
Gabriel Vela had just stabbed Casillas once in the heart, causing a three-inch perforation to the right ventricle.
Vela told police he acted in self-defense.
"This does not look like a man who's in fear," says Prosecutor Amy Freeman. "This looks like a man who is provoking, who is inciting and who is challenging those boys to a fight."
Casillas and a friend had gone looking for someone to buy them alcohol to extend a party.
Vela offered to help, but when he couldn't deliver, there was a dispute over money.
Casillas and his friend knocked Vela down and then surveillance video showed them walking away.
They threw Vela's bike and kicked his backpack.
After they got in their BMW, Vela picked up a knife and threw a heavy old phone at the car.
His attorney says that wasn't meant to start a second fight, but when it did, Vela used the knife to defend himself.
"He was just angry," says Jonathan Richter. "When Isaiah charged at him, he displayed the knife openly in the hope that seeing the knife, Isaiah might back off."
But Freeman says Vela was provoking a fight and he planned exactly how it would end.
"He was angry because he was disrespected," she said. "He was a gang banger. He has been to prison. And now, at this stage of his life, these two skinny boys jump him, in his words, and disrespect him?"
Vela has a prior felony strike, so if he's convicted of first-degree murder, he could face a sentence of 51 years to life in prison.
Jury deciding between murder and self defense from Fresno 2019 stabbing