Brookes Colby Shumway sat motionless as prosecutors called him a liar, alleging he stabbed his friend Christopher Ray 39 times and then watched as he died.
Shumway, 16, is accused of killing 14-year-old Ray during a sleepover at Ray's home Jan. 23. Though 15 at the time of the stabbing, Shumway is being tried as an adult.
Prosecutor Katherine Bernards-Goodman admonished the jury not to be swayed by Shumway's youth.
"The defendant is 16 years old," Bernards-Goodman said. "But he has been found by a court of law to be an adult and is to be treated as an adult."
Shumway has offered varying accounts of the events leading up to Ray's death, including assertions that he acted in self-defense, that there was an argument and that others were involved.
Bernards-Goodman, in her opening statement, said the evidence gathered by investigators contradicts all of Shumway's accounts.
"We know the defendant killed the victim, and it was not self-defense," Bernards-Goodman said. "We also know that the defendant has not told a true story yet. And the reason he hasn't is because he knows the true story will get him convicted."
Defense attorney Randall Lund in his opening argument seized one statement by Bernards-Goodman, in which she told jurors "to not get caught up in the details." Lund argued it is the details of the case that will set his client free, that vital omissions in the case tell as powerful a story as the gruesome details included as evidence.
Namely, Lund pointed to the medical examiner's opinion that two knives were used in the killing and that one or more people may have been involved in causing these deaths. Only one knife was found at the scene.
"The best evidence isn't available," Lund said. "It isn't available because it was ignored."
Lund also focused on the apparent silence during the time the murder was committed. The incident took place at Ray's trailer home, while his mother, sister and "yappy" poodles slept in nearby bedrooms.
"This terrible, awful incident took place without anyone hearing anything," Lund said. "There were no screams, no yelling, no commotion. No barking dogs. Nothing.
"This case is full of questions," Lund said. "The evidence is either inconclusive or raises other questions we don't have answers to."
Ray's mother and sister were scheduled to testify Tuesday. The trial is expected to conclude Friday.