OAKLAND — The families of two teen girls who were best friends and together when they were gunned down in Oakland in 2012 cried in court Thursday as their girls’ killer was convicted of murder.

After two days of deliberations, the jury found Diantay Powell, 21, guilty of first-degree murder in the shooting death of Bobbie Sartain, 16, and second-degree murder of Raquel Gerstel, 15, on Nov. 25. 2012 in Oakland. The jury also found that the special circumstances of multiple murders apply in the case, which means that Powell faces life in prison without the possibility of parole.

“That’s what we were hoping for,” Raquel’s father, Barton Gerstel, said outside the courtroom Thursday. “We’re grateful for what we got.”

Bambi Sartain, Bobbie’s mother, sobbed in the back row of the Oakland courthouse Thursday when the court clerk read the verdict.

“Justice was served,” she said. “But it won’t return my daughter. Nothing is going to bring her back.”

Prosecutor Melissa Dooher said she is relieved and thrilled “that the special circumstance finding will keep Powell in prison for the rest of his life.”

Raquel and Bobbie were sitting in a parked car with Powell near Brookdale Park in East Oakland early on that Sunday morning when they were killed. While they were all together, Powell, who had a sexual relationship with Bobbie at the time, got a phone call from another girlfriend.

Powell told the girls to get out of the car and leave, but they refused. As they argued, Powell tried to grab Bobbie and force her out of the car, prosecutor Dooher said during the trial. When Raquel came to her defense, Powell threatened her and then shot her in the head.

Bobbie ran away, screaming and begging for her life, telling Powell that she wouldn’t tell anyone what happened. But Powell chased after her, then shot her multiple times. She was shot 14 times.

In her closing arguments earlier this week, Dooher said the two girls were “slaughtered by a monster.”

She described the events that night, telling the jury that when Powell first became angry with Raquel, he went around the car into the front seat to grab his gun. She pointed out that those actions showed premeditation on his part, a requirement for a first-degree murder conviction.

Defense attorney Darryl Stallworth had argued that in an initial police interview in December 2012, a witness said Powell was already carrying the gun and pulled it out, rather than going to get it from the car.

Stallworth agreed in his opening and closing statements that there was no question Powell was responsible for the two girls’ deaths. But he sought voluntary manslaughter charges instead of murder charges, arguing that Powell was high on drugs and cough syrup at the time of the killings.

He also said Powell suffered from “complex trauma disorder” because of his history of parental neglect, slow development, lack of education and drug use at an early age.

The jury ended up favoring a ruling of second degree-murder in Raquel’s death, and first degree murder in Bobbie’s death.

Powell is expected to be sentenced on July 29.

Angela Ruggiero can be contacted at 510-293-2469 or twitter.com/aeruggie