ALLENTOWN -- When Jamie Silvonek's then-best friend was questioned by detectives about the murder of Silvonek's mother, she couldn't believe what she was hearing.
A week before the March 15, 2015, killing, the eighth-grader, who is not being identified because she's a juvenile, overheard Silvonek talking on speaker phone with her soldier boyfriend Caleb Barnes.
During their conversation, Silvonek, then 14, came up with the idea that she and Barnes, 20 at the time, should kill her parents so they could continue seeing each other, the girl testified.
Cheryl Silvonek, Jamie's mother, had forbidden them from seeing each other after catching them in bed together the night before and because of their age difference.
"We would joke all the time and I didn't think she would go through with something like this," the girl testified on the second day of Barnes' homicide trial in Lehigh County Court. "I thought it was a joke."
The former friend, now 15 and heading to 10th grade, testified she was in the basement of the Silvonek house on a sectional couch with Jamie Silvonek on March 7, 2015, and heard at least two conversations in which Silvonek and Barnes discussed the plot. The girl testified Barnes refused at first, but as they continued talking, "he became more open to the idea." By the end of the conversation, Barnes said, "he already had the knives picked out."
The next day, and one more time that week, Silvonek told her friend the conversation with Barnes was a joke. But by then, the friend testified, she was starting to lose trust in her friend because she was turning on people and never seemed to face consequences for her actions.
As the second day of the trial came to a close, a county detective who specializes in cellphone data recovery testified that he retrieved a number of deleted text messages between Barnes and Silvonek in which they continued to discuss the plot.
"No, that would leave us as the suspects," one of the last messages Barnes sent to Silvonek read.
Earlier Wednesday, Cheryl Silvonek's neighbors testified they heard her fighting for her life -- they just didn't realize it at the time.
Two people looked out the window and one man even stepped into his yard, unaware that just yards away the 54-year-old Upper Macungie woman was being beaten and stabbed in her sport utility vehicle, allegedly by her daughter Jamie and Barnes.
Two neighbors said they heard the irregular beeping of a car horn for 15 to 20 minutes outside Silvonek's Randi Lane home just after midnight on March 15, 2015.
Michelle Mueller, who lives across the cul de sac from the Silvonek house, told jurors that a set of "short beeps" woke her up shortly after midnight. Figuring someone was just locked out at the Silvonek home and trying to get in, she went back to bed.
The beeping continued, however, and was followed by a "clanking" sound coming from the Silvonek garage. Mueller said she got out of bed and looked out the window. Jamie Silvonek was walking next to her mother's SUV, which had its headlights on.
Mueller said the teen didn't seem rushed or panicked.
"She walked calmly," Mueller said. "She was fine."
Wednesday's testimony painted a chilling picture of a murder unfolding in a quiet suburb as neighbors slept. In an attack prosecutors say lasted 20 minutes, the married mother of two was beaten, choked and stabbed at least five times.
Jurors also watched Barnes' taped interview with investigators and heard him -- exhausted and disheveled -- detail the previous night when he said he stabbed Cheryl Silvonek.
Forensic pathologist Barbara Bollinger testified Cheryl Silvonek's hands and wrists were covered in defensive injuries, as if she were trying to ward off an assailant.
Both of Cheryl Silvonek's wrists were ringed with bruises, consistent with them being gripped tightly before she died, Bollinger told the jury.
Along with five stab wounds, including two fatal gashes that pierced her carotid artery and windpipe, Cheryl Silvonek's face and neck bore bruises from being hit, and eye hemorrhages consistent with being strangled, the doctor said.
Bollinger said the blood pattern was consistent with Cheryl Silvonek being seated in the driver's seat when she was stabbed in the throat, and the person holding the knife positioned behind her and to the right.
The doctor said she could not say if Barnes was the one who carried out the stabbing.
Barnes, now 21, has blamed Jamie Silvonek for Cheryl Silvonek's murder. His attorney, Richard Webster, told jurors Tuesday that Jamie Silvonek is a manipulative liar who is trying to pin the blame on his client.
Webster conceded that Barnes, an Army specialist who was stationed at Fort Meade in Maryland at the time of the killing, helped his girlfriend clean up the crime scene and bury her mother's body.
Jamie Silvonek, now 15, is the youngest girl ever charged as an adult with homicide in Lehigh County. She pleaded guilty to first-degree murder and related charges in February and was sentenced to 35 years to life in a state prison.
As part of a plea deal, she agreed to testify against Barnes.
Authorities said the slaying occurred as the mother sat in her SUV with the couple after driving them to a Breaking Benjamin concert in Scranton, trying to persuade them to end their relationship because of their age difference.
In the taped interview with Barnes, he told detectives that he and Jamie Silvonek had fallen asleep in the car on the way home from the concert. When they arrived at the Silvonek home, Barnes said, Cheryl Silvonek told her daughter to wake up and tell him it was time to drive home.
After Cheryl Silvonek left the car and went inside, Barnes and her daughter woke up and had sex in the car, Barnes told detectives. Cheryl Silvonek then came back out to the car to see where her daughter was and caught the couple. She began attacking her daughter, Barnes said, and "wouldn't stop hitting Jamie."
Saying Cheryl Silvonek was in a sort of rage, Barnes said he got out of the car and went around to the driver side door and tried to pull her off her daughter. Cheryl Silvonek hit Barnes, he said, and he began stabbing her.
"She keeps coming at you and that's when you stabbed her in the throat?" Lehigh County detective Richard Heffelfinger asked Barnes.
"Correct," Barnes replied, slumped over his chair, shirtless and looking exasperated.
After he "did it," Jamie Silvonek "just sat there," he said.
Barnes' mother sobbed silently and wiped tears as she watched the taped interview. He turned around and grinned at her at one point of the afternoon.
Barnes is charged with criminal homicide, abuse of a corpse and related charges. Prosecutors are seeking a first-degree murder conviction and life sentence.
The trial is expected to last until Friday. There is a gag order in place that prevents the attorneys from answering questions. Court staff have not said when Jamie Silvonek will take the stand.
--Reporter J. Dale Shoemaker contributed to this report.