The prosecution rests its murder case against Derek Chauvin after 11 emotional days of testimony

• The prosecution rested its case Tuesday against the fired Minneapolis police officer Derek Chauvin.
• Medical experts said low oxygen caused George Floyd's death; officers said Chauvin violated policy.
• "Spark of life" witnesses also gave the jury a picture of Floyd as a partner, brother, and son.

The prosecution rested its case against the fired Minneapolis police officer Derek Chauvin on Tuesday, following 11 days of testimony from state witnesses.

The state's final day presenting evidence included emotional testimony from George Floyd's brother Philonise as well as a criminal-law professor and expert cardiologist.

Over two weeks, the prosecution called a long list of policing and medical experts who testified that Chauvin's use of force on Floyd was not part of Minneapolis police training and that Floyd's death last May was the result of the officer's actions.

Chauvin, who's accused of killing Floyd by kneeling on his neck for more than nine minutes, is charged with murder and manslaughter.

His defense will most likely be focused on convincing jurors that Floyd's drug use and high blood pressure contributed to his death. Several prosecution witnesses already testified that neither was a factor.

Medical experts said low oxygen caused Floyd's death

The prosecution's medical experts - whose focuses included breathing, heart conditions, and autopsies - told the jury that Floyd died because he was held in a position that didn't allow him to breathe.

The witnesses explained that breathing becomes a challenge when a person is prone on the ground with their hands cuffed behind their back. They said difficulty breathing, paired with the added pressure of Chauvin's knee on his back and neck, was what caused Floyd to die.

Anticipating that the defense would try to blame Floyd's death on high blood pressure and drug use, the state also made sure its witnesses shot down that theory.

Dr. Martin Tobin, whose career has been centered on the science of breathing, testified last week, "A healthy person subjected to what Mr. Floyd was subjected to would have died."

Dr. Jonathan Rich, a cardiologist and one of the state's final witnesses, testified Monday that while Floyd had high blood pressure, his heart was "exceptionally strong."

Law enforcement and use-of-force experts said Chauvin violated policy

Minneapolis police leaders, including Chief Medaria Arradondo, told jurors that Chauvin violated department protocol in his interaction with Floyd.

Several of these witnesses said Chauvin should have stopped restraining Floyd as soon as he stopped resisting.

Officers are required to render aid during emergencies, and witnesses said Chauvin broke another department policy by not rendering aid to Floyd.

Medics testified that by the time they arrived, Floyd had no pulse, and none of the officers on scene had begun CPR. Chauvin continued to hold Floyd to the ground even after an ambulance arrived, they said.

Jurors learned about Floyd as a partner, brother, and son

Prosecutors also called two "spark of life" witnesses who shared more intimate details about Floyd's life.

The first was his former girlfriend, Courteney Ross, who told a story about the day they met and how Floyd offered her kindness at a difficult time in her life. She also shared that she and Floyd struggled with opioid use and had tried time and time again to stop using drugs.

Floyd lived an active life, and an injury to his back spurred his opioid addiction, she said.

Floyd's younger brother, Philonise, also gave emotional testimony about their upbringing.

He told the jury that while growing up, Floyd made sure all of his siblings got to school on time and didn't go hungry.

Both he and Ross described Floyd as extremely close to his mother and devastated by her death in 2018. Floyd called out for his mother in his last moments alive, according to video recorded at the scene.

"Every mother loves all of her kids, but it was so unique how they were," Philonise said of his mother's and brother's bond. "He showed us how to treat our mom, and how to respect our mom."