A Montgomery County Court jury on Thursday convicted a King of Prussia man of first-degree murder in the killings of a grandmother and 10-month-old girl, a case that prosecutors said began as a kidnapping plot and spiraled quickly into brutal violence.

Raghunandan Yandamuri, 28, a former information-technology worker who came to the United States from India on a work visa, faces the possibility of the death penalty for the 2012 stabbing of Satayrathi Venna, 61, and suffocation of her granddaughter, Saanvi Venna.

Yandamuri appeared emotionless for most of the trial in Norristown and displayed no reaction to the verdict. His mother, who had traveled from India and has been in the front row of the courtroom each day, broke into tears and began sobbing. Yandamuri did not look at her.

First Assistant District Attorney Kevin Steele said the verdicts would help the victims' family heal.

"It's been a long struggle for them," he said. "Justice was done today."

Yandamuri represented himself during the trial, but he will be represented by attorney Henry S. Hilles during the penalty phase, which began immediately after the verdict. Jurors will return to court Friday to hear testimony and consider whether to sentence Yandamuri to death.

Yandamuri confessed to the crimes early on, then recanted and blamed the killings on two men who he said forced him to help them. On Thursday, Hilles said Yandamuri was stunned by the jury's decision.

"He thought that he was going to have a different verdict," he said. "Whether or not that seems plausible to court observers is debatable."

When Yandamuri fired his attorney in May, the judge overseeing the case, Judge Steven T. O'Neill, warned him against it, and some feared the trial would become a circus.

Yandamuri seemed prepared for each day's proceedings, and as he questioned witnesses and raised objections, he demonstrated that he had studied legal terms and guidelines. But when it came time to tell jurors his side of the story, he focused on seemingly minor details and barely talked about the men he claimed were the real killers.

During the trial, which opened with jury selection Sept. 16, prosecutors presented DNA evidence that they said linked Yandamuri to the murders, as well as surveillance footage that contradicted Yandamuri's defense, and a confession in writing and on video. They said Yandamuri's confession led police to the body of the infant, as well as to gold jewelry he stole from the family's apartment.

Steele and Deputy District Attorney Samantha Cauffman painted Yandamuri as a cold, calculating killer who preyed on the most vulnerable members of a family that had shown him kindness when he and his wife moved to their apartment complex.

They showed jurors records proving that Yandamuri was a frequent gambler who lost large sums of money in the days before the murders. When his need for money became overwhelming, they said, he decided to kidnap the baby and kill the grandmother because she would have been able to identify him.

Armed with a kitchen knife and dressed in a hoodie, Yandamuri got into the Venna family's apartment and slashed through the woman's neck so deeply that he struck bone. He then stuffed a handkerchief into the baby's mouth, zipped her into a suitcase, and left with her. Prosecutors suggested that he kept the child in the trunk of his car for days before leaving her in an empty, trash-strewn sauna elsewhere in the apartment complex.

After Montgomery County detectives approached Yandamuri as one of several suspects, he confessed during a 17-hour interview session.

The case went to jurors Wednesday, but after a problem arose during deliberations, O'Neill replaced one juror with an alternate Thursday. Once the reconstituted jury was set, jurors took about six hours to reach a decision.

Yandamuri's mother, Padmavathi, took the stand briefly Thursday as the first witness in the sentencing phase. Speaking through an interpreter, she tearfully told jurors that Yandamuri's father, a police officer, was killed in a terrorist attack when her son was 10. The death traumatized Yandamuri, who stopped sleeping and attempted suicide a year later by drinking kerosene, she said. He was put on medication that helped him, she said, but he stopped taking it at some point.

"Please save my son somehow," she begged the jury, weeping.

As she spoke, Yandamuri put his head in his hand and covered his eyes.

610-313-8113 @AESteele