A 22-year-old soldier who spoke Farsi and worked for the National Security Agency was convicted of first-degree murder in Lehigh County Friday.

Jurors found Caleb Barnes guilty of murdering Jim Thorpe native Cheryl Silvonek as part of a plan hatched with Silvonek's then-14-year-old daughter, Jamie.Jurors returned a verdict after about four hours of deliberating Friday evening, convicting Barnes on all counts. In addition to first-degree murder, he was convicted of conspiracy to commit first-degree murder, tampering with evidence, and abuse of a corpse.About three hours into deliberations, jurors asked Judge Maria Dantos to clarify the difference between first- and third-degree murder. Dantos explained that first-degree murder means the defendant had an intent to kill.Prosecutors said that Barnes and Jamie Silvonek killed Cheryl Silvonek in her car in the driveway of her Upper Macungie Township home in the early hours of March 15, 2015.Barnes showed no emotion after the verdict was read. His parents, who came from Texas and watched the entire trial from the gallery, wept quietly.Prosecutors said Barnes and Silvonek decided to kill Cheryl Silvonek because she disapproved of her 14-year-old daughter dating a 20-year-old man.Senior Deputy District Attorney Jeffrey Dimmig said that Cheryl Silvonek confronted Barnes about the age difference and threatened to call the police, which gave him the motivation to kill her."Barnes told many different versions of the story. The truth convicts him. The evidence in this case is the truth. And the truth is that he stabbed and killed Cheryl Silvonek," Dimmig said in his closing statement.Text messages extracted from the couple's phones suggested that Silvonek came up with the idea, but that Barnes went along with it. Silvonek's former best friend testified that she overheard them discussing it on a call about a week before the murder.Silvonek has already pleaded guilty to first-degree murder. She is serving 35 years to life.She took the stand Friday morning, called by Barnes' defense attorney. That was notable in itself because she was expected to testify for the prosecution after accepting a plea deal in February that helped her avoid a life sentence.She admitted to lying throughout the investigation, and pushing Barnes toward committing the murder."I didn't have any involvement in the physical act, but I believe everything I did was worse than the physical act itself," the 15-year-old said on the stand.Barnes also took the stand Friday, presenting a version of events that was not previously reported. He said that after returning from the concert, Cheryl Silvonek asked him to leave.He said that because it was 1 a.m., he fell asleep in his car outside the home. He said he was awakened by Jamie Silvonek, who said she had killed her mother after an argument. Barnes said he was obligated to help because he loved Jamie, and she told him that she was pregnant."He told you that he lied, he lied to protect Jamie Silvonek," Barnes' public defender, Richard Webster, said.Cheryl Silvonek's body was found only a few hours after the killing, because a person who lived near where she was buried saw the parked car that Barnes and Jamie Silvonek drove to bury her.The car was found about 2 miles away. That led police to the Silvoneks' home, where they found Barnes and Jamie Silvonek in bed together.Jamie's father, David, was asleep in the house while his wife was murdered outside.Through text messages and video surveillance, prosecutors learned that Cheryl Silvonek had just driven the couple back from a concert in Scranton. Silvonek's text messages showed they were discussing the killing that day."She needs to go Caleb, right now. You don't understand," one read."She threatened to throw me out of the house, I want her gone."Prosecutors used Barnes' text messages to argue that Cheryl Silvonek told him Jamie's true age, and he was worried that it would jeopardize his job at the NSA."She can't fake a passport Jamie," one of the text messages read.Prosecutors also played jailhouse phone calls in which Barnes discussed the murder. He told his mother in one call that telling the truth would get him a life sentence."I only remember doing it twice, and there are four of them. It was kind of a blur," Barnes told a friend who visited him in jail.Forensics experts testified in the case that they found significant amounts of Cheryl Silvonek's blood on a jacket that Barnes had next to him when he was arrested.A forensic pathologist said that Silvonek was killed by stab wounds to the neck, probably inflicted by someone sitting directly behind her in the car. Prosecutors argued that's where Barnes was sitting in the car.At the time of the murder, Barnes was a soldier stationed at Fort Meade, Maryland, working for the NSA. He testified that he knew, and taught, the Farsi language, which is spoken widely in the Muslim world, particularly in Iran and Afghanistan.His childhood best friend, Joshua Mix, testified that they met Silvonek at a concert in Philadelphia in October 2014, shortly after he transferred to Fort Meade.Mix testified that Silvonek told them she 'was about to turn 18,' when she was actually 13 at the time.The pair cultivated their relationship by meeting in Jim Thorpe, where Jamie's grandmother, Cheryl's mother, lives. Barnes' cellphone showed he was in the Jim Thorpe area about once a month between October 2014 and February 2015.Barnes will be sentenced Sept. 19. First-degree murder carries a mandatory life sentence.Dantos also lifted a gag order, which forbid attorneys from speaking to the media about the case.