Charges were elevated to second-degree murder against Derek Chauvin, a former Minneapolis police department officer who was recorded kneeling on the neck of a handcuffed George Floyd for more than eight minutes, Minnesota Attorney General Keith Ellison said Wednesday.

Arrest warrants were issued for three additional former Minneapolis police officers for aiding and abetting second-degree murder, he said.

“Trying this case will not be an easy thing,” given the difficulty of convicting a police officer of murder, he said. “History does show that there are clear challenges here and we’re going to be working very hard. “

“George Floyd mattered,” Ellison said. “He was loved. His family was important. His life had value. We will seek justice for him, for you.”