derrek chauvin betrayed this badge when he used excessive and unreasonable force up on the body of mr. george floyd. >> reporter: the prosecution's opening statement tells everything they need to know how they want the jury to see this

final choke in while he was on top to get the kill choke. >> reporter: for the defense's case. >> derrek chauvin did exactly what he had been trained to do over the course of his 19-year career. the use of force is not attractive, but it is a necessary component of policing. >> reporter: chauvin's attorney made clear this will also be a battle of experts. >> this will ultimately be another significant battle in this trial. what was mr. floyd's actual cause of death? >> reporter: he wants the jury to look at the whole scene and listen to the use of force and medical experts, as well as read the medical reports. >> that revealed mr. floyd had an exceptionally high level of carbon dioxide. dr. baker found none of what are referred to as the telltale signs of asphyxiation. there was no hemorrhaging, there was no evidence that mr. floyd's air flow was restricted. >> reporter: instead, he suggested it was elicit drugs found in floyd's system that aggravated a medical condition that took his life. >> hypertension, the injection of methamphetamine and fenlt until and adrenaline going through his body, a

minneapolis is under watch this morning as the trial of derrek chauvin gets under way nbc's gabe gutierrezs in minneapolis with the latest. gabe, good morning >> reporter: philip, good morning. thisg a police officer in recent history. edge. barricades surround the minneapolis courthouse where jury selection is set to begin on the jury trial of derek chauvin, a man prosecutors say knelt on george floyd's point for about nine minutes mayor jacob frey and others have been preparing for months. >> this is perhaps the most significant moments in entire history. >> reporter: watching the video. >> blood is coming from his nose, the officer still sat there on his neck like it was okay it's never okay to hurt somebody like that. we shouldn't have to go to court for anything like this >> reporter: chauvin is charged with second degree murder and manslaughter his attorney is declining to comment but has previously said in court filings that floyd endangered officers by resisting arrest in august, three other officers are scheduled to stand trial on thomas lain points to floyd had amphetamine in his