A classmate of Jamie Silvonek's testified Wednesday that one week before Cheryl Silvonek was killed she overheard the 14-year-old planning the deadly attack with her boyfriend.

"She said 'what if my parents were killed,'" the friend, a rising 10th-grader at Parkland High School, said."He wasn't into the idea at first. As time went on, he was getting more and more OK with the plan to kill her parents."Silvonek's body was found in a grave along a Lehigh County Creek the morning of March 15, 2015.That afternoon, her daughter's boyfriend, Caleb Barnes, admitted to police that he stabbed her.In the second day of testimony of Barnes' murder trial, prosecutors continued their case against Barnes. Jurors heard the interview where Barnes admitted to fatally stabbing Cheryl Silvonek, a Jim Thorpe native.Jamie Silvonek has already pleaded guilty to first-degree murder. Many expect her to testify in the Barnes trial, but there has been no indication when she will.During about six hours of testimony on Wednesday, the prosecution argued that while both parties came up with the plan to kill Cheryl Silvonek, it was Barnes who stabbed her five times in the neck as they sat in a car outside the Silvoneks' home on an upscale cul-de-sac in Upper Macungie Township.Jurors were given transcripts of the interview with Barnes because the audio and video quality were poor.Throughout the interview, Barnes seems more interested in protecting Silvonek than himself, repeatedly asking the detectives whether she will be charged.At times on the tape the detectives argue with Barnes. Lehigh County Detective Richard Heffelfinger can be heard sternly telling him, "This is over, Caleb. Jamie told us everything. You can either tell us what happened or you're going down as a coldblooded killer."Barnes ultimately admitted on the tape to stabbing Cheryl Silvonek, but he said that it was a crime of passion because she was attacking Jamie after catching the two just minutes after they had sex in Cheryl's car.Prosecutors say that the crime was actually a premeditated murder. They believe that the couple conspired to kill Cheryl Silvonek after she became aware of Barnes' real age, which was 20 at the time. Silvonek told her mother that Barnes was 17.Barnes also said that he believed that Jamie was 17 up until the morning after the alleged crime, when police pulled them out of bed and asked them their ages.Cheryl Silvonek was clearly concerned about their relationship. Police extracted data from her phone and found a note with Caleb Barnes' name, the license plate of his vehicle, and what looks like a Social Security number.A detective said that the phone data showed that approximately one week before the murder, Cheryl Silvonek did a Google search for "My 14-year-old daughter and her boyfriend are exchanging sexual text messages. Should I be spying on her?"Prosecutors have also pointed to the fact that Jamie's passport was found sitting open on Cheryl's dresser. They believe that she showed it to Caleb before the murder, based on a text message to Jamie, extracted from his phone, that says "Jamie, she can't fake a passport."Barnes and Silvonek both deleted all the text messages that they sent on March 14, which also may indicate a conspiracy.A detective recovered the messages as part of an extensive search of the messages that they sent each other. They exchanged about 6,000 text messages over the five plus months they were dating, according to Paul Iannace, a county detective and digital forensics expert.A pathologist testified that Cheryl Silvonek died from the knife wounds that severed her carotid artery. She testified that it appeared that the stabbing came from the seat behind Silvonek. A picture recovered from Jamie's phone showed Barnes sitting in that seat around 6 p.m. that evening as Cheryl Silvonek drove them to a concert in Scranton."Based on your report, you do not know who attempted to strangle Cheryl Silvonek," defense attorney Richard Webster asked the expert, who replied no. "Based on your report you do not know who stabbed Cheryl Silvonek," Webster asked.The reply was no.Neighbors who lived next to and behind the Silvoneks' house testified to hearing repeated beeping coming from a vehicle outside around 1 a.m. on the morning of the murder.Both Ibrahim Kheir and Michelle Mueller got up to see if someone was locked out of a house. But when the beeping stopped, they both returned to what they were doing. They said the beeping car was parked in the right hand side of the driveway.Jamie's grandmother, Margaret Lynn of Jim Thorpe, recalled that was where Cheryl always parked her vehicle.Lynn was upbeat on the stand, and recalled baby-sitting Jamie since she was a child. She had never heard of Barnes, but she did drop off Jamie at the Jim Thorpe Fall Festival in 2014, which is one of the places they are believed to have hung out during their relationship."I was very close with Jamie. We were together constantly," she said.