MINNEAPOLIS (AP) — Two former Minneapolis police officers charged in George Floyd’s death are heading to trial on state aiding and abetting counts, the third and likely final criminal proceeding in a killing that mobilised protesters worldwide against racial injustice in policing.

J Alexander Kueng and Tou Thao have already been convicted of federal counts for violating Floyd’s civil rights and begun serving those sentences. Many witnesses expected to testify at their state trial have already done so at both their federal trial and at the state trial against their former colleague, Derek Chauvin.

While much of the evidence in this proceeding will look similar, there will be some key differences.

Here are a few things to know as jury selection gets underway Monday:

Kueng, Thao and Thomas Lane were working with Chauvin on May 25, 2020, when Chauvin, who is white, used his knee to pin Floyd’s neck to the pavement for more than nine minutes as the 46-year-old Black man said he couldn’t breathe and eventually grew still. Kueng knelt on Floyd’s back, Lane held his legs and Thao kept bystanders back.

Kueng, who is Black, and Thao, who is Hmong American, are each charged with aiding and abetting second-degree unintentional murder and aiding and abetting second-degree manslaughter. Prosecutors will have to prove they intentionally helped Chauvin. They don’t have to prove that they intended to kill Floyd or cause him great bodily harm.

Chauvin was the first officer to face trial in a livestreamed, weekslong proceeding filled with emotional testimony from bystanders, graphic video of Floyd’s dying moments and expert testimony about use of force as well as the mechanics of breathing. He was ultimately convicted of murder and manslaughter.

The second trial in Floyd’s death came in federal court, where Lane, Kueng and Thao were all convicted of federal civil rights violations.

“It’s going to be, I think, exhaustingly repetitive for the witnesses who have already testified multiple times and don’t want to relive this,” said Rachel Moran, a professor at the University of St. Thomas School of Law.

But there will be some nuances. Moran said this case could be more difficult for prosecutors: While Chauvin’s offense was more direct because he had his knee on Floyd’s neck, prosecutors in this case have to show what Kueng and Thao intentionally did to help him commit a crime.

Judge Peter Cahill has limited expert witnesses to try to avoid repetition. He’s also ordered attorneys not to ask questions designed to elicit emotion.

Witnesses won’t be allowed to ask the jury to take actions and follow along with demonstrations – as lung and critical care specialist Dr Martin Tobin did during Chauvin’s trial. In that case, Tobin placed his hands on his own neck and encouraged jurors to do the same as he explained how he believed Floyd died. Jurors said later that Tobin provided some of the trial’s most compelling evidence.

It’s also unknown if a girl who was just 9 at the time of Floyd’s killing will testify. Prosecutors want to call her to argue that even a young girl knew something was wrong – so the officers should have known as well. The defense has countered that her testimony isn’t that different from that of other bystanders and will only play upon jurors’ emotions. She previously testified at Chauvin’s trial.