The African American G. Floyd, whose death caused unrest in the United States, died of pressure-induced oxygen deficiency, according to an independent post-mortem examination of the body.

The death of Floydo, suspected of trying to buy cigarettes for a forged check, in the United States on May 25 sparked a wave of protests against systemic racism and police violence.

“Minnesota Attorney General Keith Elison has turned the charges against Derek Chauvin into second-degree murder charges. The other three officials have also been charged,” Senator Amy Klobuchar said on Twitter on Wednesday.

“This is another important step towards justice,” he added.

Last week, Chauvin was charged with third-degree murder, which is essentially the same as the charges of unintentional murder.

Second-degree murder charges do not imply premeditated murder, but in this case, more severe penalties are imposed.