DES MOINES, IOWA — Prosecutors on Thursday sought to create a concrete forensic connection between Preston Walls and the shooting deaths of his classmates Rashad Carr and Gionni Dameron at Starts Right Here in Des Moines on January 23rd. Walls is charged with two counts of First Degree Murder as well as Attempted Murder, Willful Injury and Criminal Gang Participation.

Police say Walls killed the two fellow teens as part of an escalating dispute between rival gangs. That escalation included the recording of a “dis-track” produced by the victims using equipment at the educational center where the shooting occurred. On Thursday, the jury was walked through further evidence of the alleged gang “beef”. Social media posts and cell phone videos from known gang members were played for jurors. Police say the videos contained numerous implied threats from one gang to one another.

Walls’ defense again asked the judge to declare a mistrial based on the testimony on a police officer. On Thursday, an officer referred to the scene of the shooting as a “murder” scene as opposed to a “homicide” scene. The motion was denied multiple times by the judge, who found the officer made a poor choice of words but hadn’t tainted the trial.

The day began with testimony examining the autopsies performed on the bodies of Carr and Dameron. The cause of death for both teens was multiple gunshot wounds. Jurors were also walked through ballistic evidence collected in the investigation into the shootings.

Walls faces an automatic sentence of life in prison without the possibility of parole. Co-defendant Bravon Tukes, who drove Walls from the scene of the shooting, is facing the same charges as Walls. His trial is scheduled to begin in October.