A day-by-day recap of the Derek Chauvin murder trial

After nearly three weeks of testimony, the defense rested its case Thursday in the murder trial of former Minneapolis police officer Derek Chauvin for the killing of George Floyd in south Minneapolis on May 25, 2020. Chauvin is charged with second-degree unintentional murder, third-degree murder and second-degree manslaughter. Jury selection in the trial began March 8, with opening statements on March 29. Three other fired officers who assisted in Floyd's 2020 arrest — J. Alexander Kueng, Thomas Lane and Tou Thao — are scheduled to be tried in August on charges of aiding and abetting murder and manslaughter.

Closing arguments are slated for Monday, after which the jury will begin deliberating. Here's a recap of each day's testimony in the trial. You can watch a replay of the full proceedings from each day here.

1. Jena Scurry, the 911 dispatcher who handled the call that resulted in Chauvin and the other officers responding to the intersection where Floyd was detained. Jena Scurry detailed how she was troubled by seeing on wall-mounted dispatch screens how Floyd's arrest played out on city surveillance cameras. She said she glanced up at the screens and saw a police squad moving "back and forth" as officers dealt with Floyd, then moments later take him to the pavement. Multiple times she looked away and then back to see the same image of the officers keeping Floyd on the pavement. It was then that "something was not right. It was an extended period of time," she said. "It was a gut instinct, now we can be concerned." Scurry said she called a supervisory sergeant and reported what she saw. "I don't know, you can call me a snitch if you want to but we have the cameras up for [squad] 320's call, and … I don't know if they had to use force or not, but they got something out of the back of the squad, and all of them sat on this man, so I don't know if they needed you or not, but they haven't said anything to me yet," the dispatcher is heard by the jury saying in her call to the sergeant.

2. Alisha Oyler, a Speedway employee at 38th and Chicago who witnessed Floyd's arrest and testified that she recorded several brief video clips of Floyd's arrest and turned them over soon after to police. Oyler said under prosecution questioning that she made the videos because "police is always messing with people ... and it's not right."

3. Donald Williams II, a witness at the scene of 38th and Chicago who urged Derek Chauvin to get off Floyd's neck and to check Floyd's pulse. Williams told the court that as a longtime mixed martial arts fighter he was familiar with how Chauvin had Floyd pinned to the pavement. Williams recognized it from his training as a "blood choke." He added it can lead to someone falling unconscious. "You see Floyd fade away like the fish in the bag," he said. "He vocalized that he can't breathe and 'I'm sorry.' His eyes rolled back in his head." As Williams watched the viral video shot by a fellow bystander, he told the court that Chauvin was shifting his weight on purpose repeatedly to tighten the hold on Floyd's neck, what the witness called a "shimmy."

1. Darnella Frazier, the teenager, now 18, who filmed the video seen worldwide of Floyd's death outside Cup Foods. "When I look at George Floyd I look at my dad, I look at my brothers, I look at my cousins, my uncles because they are all Black," she said. "I have a Black father, I have Black brothers, I have Black friends. I look at them and how it could have been one of them. It's been nights I've stayed up apologizing to George Floyd for not doing more and not physically interacting and not saving his life, it's not what I should have done it's what he should have done." Nelson was brief in his cross-examination, crafting his questions to set the scene as becoming increasingly hostile to the point of creating a potential threat to the officers. Frazier agreed with Nelson that bystanders were getting louder and more angry, but she added that she didn't think anyone was ever threatening to Chauvin.

2. Judeah Reynolds, Frazier's 9-year-old cousin who also witnessed Floyd pleading for his life. "I was sad and kind of mad and it felt like it was stopping his breathing and it was hurting him," she said. Defense attorney Eric Nelson did not cross-examination the girl, who was then excused.

3. Alyssa Funari, a witness to Floyd's death who was 17 at the time and began recording with her cell phone. Her previously unseen footage was played in court. "It was difficult because I felt like there wasn't really anything I could do," she said. "As a bystander I was powerless there, and I was failing to do anything."

4. Kaylynn Gilbert, who was also 17 when she arrived at Cup Foods with Funari. She said she had a "gut feeling" that something was wrong. "I saw (Chauvin) digging his knee into (Floyd's) neck more. He was putting a lot of pressure into his neck that was not needed."

5. Genevieve Hansen, a Minneapolis firefighter who was off-duty when she encountered the scene and attempted to render aid to Floyd, but was rebuffed by officers. "There is a man being killed, and I would have been able to provide medical attention to the best of my abilities, and this human was not provided that right," she said. Hansen, 27, a two-year member of the Fire Department, testified that Chauvin appeared "very comfortable with the majority of his weight balanced on top of Mr. Floyd" while pinning him to the pavement with his knee.

In his cross examination of Hansen, defense attorney Eric Nelson raised potential inconsistencies in her testimony compared to previous statements to investigators, such as whether Chauvin had one hand in his pocket, or whether or not she described the bystanders as comprising a "heavy crowd." He also reminded Hansen that she earlier described Floyd as a small man, despite his being roughly 6 feet 3 inches tall and weighing well more than 200 pounds.

He asked her whether she ever had a citizen yell at her or tell her she was doing her job wrong while fighting a fire. She repeatedly said that it would not faze her, because she is confident in her training. After exchanges with Nelson that grew testy at times, Judge Peter Cahill dismissed the jury for the day and admonished Hansen not to argue, and that it is Nelson's job to ask her questions.

The prosecution called four new witnesses on Wednesday. They were:

1. Christopher Martin, 19, the Cup Foods clerk who sold Floyd a pack of cigarettes and suspected the $20 bill Floyd used was counterfeit. After he attempted twice to get Floyd back in the store, his manager summoned the police. Martin was seen in exterior store video footage pacing about near the arrest scene and clasping his hands atop his head. Martin said he was feeling "disbelief and guilt." Why? He was asked. "If I would have just not taken the bill, this could have been avoided."

The clerk said that when he first saw the bill, "I noticed it had a blue pigment to it, kind of like a $100 bill would have, so I found that kind of odd and assumed it was fake." Martin said store policy meant he would have to pay for any counterfeit currency he or his co-workers accepted. "I took it anyway and was willing to put it on my tab, and then I second guessed myself," he said.

2. Christopher Belfrey, 45, who was with his fiancée and picking up something to eat from Cup Food that night, when he parked behind Floyd's SUV. He began recording a video with his phone when he saw Office Thomas Lane point a gun at Floyd and pull him out of the vehicle. He then moved his car across the street to avoid "commotion" and resumed recording as the officers sat Floyd on the pavement and questioned him. "It startled me when I seen the officer raise his gun, I started recording," he said.

3. Charles McMillian, 61, who was the first witness on the scene after officers escorted Floyd from across the street, then struggled to get him into their squad car. McMillian, 61 initially encouraged Floyd to cooperate because once in handcuffs "you can't win," he testified. McMillian cried on the stand as he described feeling "helpless." He confronted Chauvin after Floyd was taken away in an ambulance.

"I think I said to him, 'Five days ago I told you at the end of the day go home to your family safe, and that the next person go home to their family safe, but today I gotta look at you as a maggot.'"

4. Lt. James Rugel, head of Minneapolis Police Department's Business Technology Unit. He was on the stand while the state played body camera videos from officers Thomas Lane, J. Alexander Kueng, Tou Thao and Chauvin.

1. Courteney Ross, George Floyd's girlfriend for the three years leading up to his death. She testified about their relationship after she met him while visiting the Salvation Army Harbor Lights shelter where he was a security guard. They both struggled off and on with opioid addiction. Both suffered chronic pain and had prescriptions when they became addicted; they then began obtaining the drugs off the street. She said Floyd typically used oxycodone and obtained them through other people's prescriptions to ensure that they were safe. Shortly before Floyd's death, they had taken a pill that acted more as a stimulant, Ross said.

"Both Floyd and I, our story is a classic story is of how we both get addicted to opioids," she testified. " ... We got addicted and tried really hard to break that addiction many times."The defense has contended that illicit drug use played a role in Floyd dying and not anything Chauvin did to him on May 25.

2. Seth Bravinder, a Hennepin EMS paramedic who responded with his partner to 38th and Chicago where George Floyd lay unconscious pinned beneath the three officers. Bravinder said "there were multiple officers on top of the patient, we assumed — I assumed — there was potentially some struggle still because they were still on top of him."

Bravinder and his partner loaded Floyd into the ambulance and began working on him. He said full cardiac arrest is "not a good sign for successful resuscitation. Basically, just because your heart isn't doing anything at that moment, it's not pumping blood. It's not a good sign for a good outcome."

Defense attorney Eric Nelson's questions addressed in part the gathering crowd at 38th and Chicago and noted that Floyd was moved quickly in the ambulance to a different location before continuing on to HCMC. The defense earlier in the trial has touched on how bystanders might have created an atmosphere that was potentially threatening to the officers at the scene.

3. Derek Smith, a Hennepin EMS paramedic and partner to Bravinder. He checked Floyd's pulse at the scene and immediately noted there was no pulse and Floyd's pupils were dilated. "I looked to my partner, I told him 'I think he's dead, and I want to move this out of here and begin care in the back,' " Smith said, noting the agitated crowd of bystanders.

However, they continued to work on Floyd in the ambulance, including directing Officer Thomas Lane to deliver chest compressions while they attempted various lifesaving attempts en route to HCMC.

Smith said Floyd never regained a pulse, but they continued attempting to save him. "He's a human," Smith said. "I was trying to give him a second chance at life."

4. Capt. Jeremy Norton, a Minneapolis Fire captain who responded to 38th and Chicago, where the ambulance carrying Floyd had already left. He encountered an "agitated to distraught" off-duty firefighter Genevieve Hansen and other bystanders. He made his way to the ambulance, where Floyd was "an unresponsive body on a cot." Afterward, he called his supervisors to report what happened.

"I was worried that a man had been killed in police custody…and then I also wanted to notify my supervisor that there was an off-duty firefighter that was a witness at the scene."

5. David Pleoger, a retired Minneapolis police sergeant in the Third Precinct who was supervisor to Chauvin and the other three officers the night of Floyd's death. He fielded concerns through 911 dispatch on May 25 about possible excessive use of force by officers while detaining Floyd. He then headed to the scene while questioning Chauvin on what happened. Chauvin did not immediately tell him that he placed his knee on Floyd's neck. The officer said Floyd was going "crazy [and] wouldn't go in the back of the squad."

When Chauvin did disclose later that night that he used his knee to hold down Floyd, he did not say for how long, the sergeant added. The sergeant, who reviewed officers' body-worn camera video, was asked when use of force against Floyd should have ended. He replied: "When Mr. Floyd was no longer offering up any resistance to the officers, they could have ended their restraint."

1. Dr. Bradford Wankhede Langenfeld, the emergency room physician at HCMC who examined Floyd and declared him dead soon after he arrived by ambulance. He said he tried various measures for 30 minutes to save his patient. He testified that Floyd never had a heartbeat "sufficient to sustain life" and he believed Floyd's cardiac arrest was due to a lack of oxygen, or asphyxia. He said he did not believe Floyd's cardiac arrest was the result of a heart attack.

"At the time it was not completely possible to rule that out," he said, "but I felt it was less likely based on the information available to us."

2. Minneapolis Police Chief Medaria Arradondo, who has led the 700-member force for the past three years. He went on the record less than a month after Floyd died and called it "murder." On Monday, Arradondo placed the responsibility for Floyd's death on Chauvin in his testimony using terms that were just as clear but less stark.

"Once Mr. Floyd had stopped resisting — and certainly once he was in distress and trying to verbalize that — that should have stopped," the chief said after spelling out department policy on when to use force vs. calming a situation through de-escalation tactics.

"There's an initial reasonableness of trying to just get him under control in the first few seconds," the chief continued, "but once there was no longer any resistance, and clearly when Mr. Floyd was no longer responsive and even motionless, to continue to apply that level of force to a person proned out, handcuffed behind their back, that in no way shape or form is anything that is by policy. It's not part of our training and is certainly not part of our ethics or values."

Under cross examination by defense attorney Eric Nelson, Arradondo acknowledged that officers sometimes need to take control of a situation. "Would you agree that the use of force is not an attractive notion?" Nelson asked.

"I would say the use of force is something that most officers would rather not use," Arradondo said. The chief also agreed that department policy affords an officer flexibility under evolving circumstances for when to use force or choose to de-escalate an encounter with someone resisting arrest.

3. Inspector Katie Blackwell, MPD Fifth Precinct Inspector, who formerly headed up training for the department when Floyd was killed. Blackwell was shown a photo from the viral video of Chauvin on Floyd's neck and was asked whether that is a tactic the police are taught.

"I don't know what kind of improvised position this is," said Blackwell, who has known Chauvin for about 20 years, when they were both community service officers.

She also walked through records showing the various training that Chauvin received in 2016 and 2018, which included when a suspected is detained facedown and handcuffed. As heard multiple times in previous testimony during the prosecution's case, the person should be put "in the side recovery position or an upright position … as soon as possible," or run the risk of asphyxiation."

1. Sgt. Ker Yang, an MPD crisis trainer who explained that listening is key to crisis intervention. Voice, neutrality, respect and trust are at the core of the model on how an officer should approach a crisis situation. "It is useful [and] it is practical," he said. "When it is safe and feasible, we shall de-escalate."

2. Lt. Johnny Mercil, an MPD use of force trainer. He is experienced in martial arts, particularly Brazilian Jiujitsu, a form of martial arts that results in leverage and body control. Derek Chauvin was on his training roster. He testified about "red zones, where injury tends to range from serious to long lasting and could include serious bodily injury or death. Areas included the head, neck and sternum, among others. Conscious and unconscious neck restraint should only be used in cases of active resistance andaggression, respectively, he said.

"You want to use the least amount of force necessary to meet your objective to control, if those lower uses of force do not work or are too unsafe to try you can increase your level of force against that person."

3. Officer Nicole Mackenzie, an MPD medical support coordinator, responsible for CPR and other classes for officers. She said police have a responsibility to both call ambulance and render aid "if it's a critical situation." She testified that being able to talk doesn't mean you're necessarily able to breathe. She testified that agonal breathing, or a brainstem reflex that causes gasping, could be misinterpreted as breathing. "Somebody could be in respiratory distress and still be able to verbalize it," she said. "Just because they're speaking doesn't mean they're breathing adequately."

4. Sgt. Jody Stiger, a Los Angeles Police Department police officer of 28 years and use of force expert hired by the state. He reviewed the materials and deemed the use of force against Floyd "excessive." Initially when Mr. Floyd was being placed in the backseat of the vehicle, the officers were justified in trying to have him comply and sit in the backseat of the vehicle," Stiger said. "However, once he was placed in the prone position on the ground, he slowly ceased his resistance and the officers—or ex-officers I should say—should have slowed down or stopped their force.

1. Special Agent James Reyerson of the Minnesota Bureau of Criminal Apprehension (BCA) and part of the agency's use of force investigation group. Reyerson testified about taking photos of Chauvin, processing videos and other evidence, including the squad and the vehicle Floyd was driving, along with items found inside the vehicle: a pill, some dollar bills, a pipe. He testified that Chauvin kept his weight on a handcuffed George Floyd's neck for minutes after Floyd was no longer talking or moving during the incident late last spring.

Defense attorney Eric Nelson also played a short clip of Floyd from Kueng's body camera during which he was pleading with the officers. Did it appear that Mr. Floyd said "'I ate too many drugs?'" Nelson asked.

"Yes, it did," Reyerson said.

When Frank later played a longer version of the video in court, Reyerson reversed course.

"Yes, I believe Mr. Floyd was saying, 'I ain't do no drugs,'" the agent said.

2. McKenzie Anderson, a BCA forensic scientist. She processed both the Mercedes Benz Floyd was in and Squad 320 on the first processing of the squad, she tested eight stains, seven of them blood, that tested positive for George Floyd's DNA. She reprocessed the squad at defense attorneys' request in January and found what appeared to be a pill and other apparent remnants in the backseat of the squad. It tested positive for George Floyd's DNA.

3. Breahna Giles, a chemical forensic scientist for the BCA. She testified that the pills found inside the Mercedes contained methamphetamine and fentanyl. The partial pill and other traces of it tested positive for methamphetamine, and in the case of the largest partial pill, another substance was detected, but there was not enough of it to conclusively identify it, she said.

Defense attorney Eric Nelson asked Giles if the trace substance was fentanyl.

"I can't confirm," she said.

"You can't say it was or wasn't fentanyl?"

"Yes," she said.

4. Susan Neith, a forensic chemist at NMS labs in Pennsylvania. She tested the two pills found in the Mercedes and the partial found in the squad. All three pills contained a fentanyl concentration of less than 1%, which she said is common. The pills contained a methamphetamine concentration of 1.9 to 2.9%, which she said was atypically low.

"The majority of the time I see 90 to 100% methamphetamine," she said.

1. Dr. Martin Tobin, a physician in pulmonology and critical care at Hines VA hospital in Chicago, and Loyola University School of Medicine. In lengthy testimony, heconcluded that "Floyd died from a low level of oxygen. This caused damage to his brain that we see, and it also caused a [pulseless electrical activity] arrhythmia that caused his heart to stop."

Floyd stopped breathing 23 seconds later and "didn't have an ounce of oxygen in his body" less than a minute after losing consciousness, Tobin said. He noted the moment Floyd died when shown the bystander video of his final moments. "At the beginning you can see he's conscious, you can see slight flickering and then it disappears, so one second he's alive and one second he's no longer," Tobin said. " ... That's the moment the life goes out of his body."

2. Daniel Isenschmid, a forensic toxicologist at NMS Labs in Pennsylvania. He testified that while fentanyl was found in Floyd's blood, so was norfentanyl, which is metabolized fentanyl. Overdose victims rarely have norfentanyl in their blood, he said. He testified that Floyd's ratio of fentanyl to norfentanyl was 1.96 ng/ml. This is compared to the average ratio of 9.05 in postmortem cases and 3.2 in driving under the influence cases. Floyd's level of methamphetamine, 19 ng/ml, was in the bottom 5.9% of a sample of DUI methamphetamine cases.

"Does this show Mr. Floyd was below the average and even below the median in DUI cases?" prosecutor Erin Eldridge asked. "Yes," Isenschmid said.

3. Dr. Bill Smock, a specialist in legal forensic medicine and former emergency room doctor at the University of Louisville's trauma center. He works as a police surgeon for the Louisville Police Department. He reviewed videos from Floyd's arrest and other case records and concluded that he died from a lack of oxygen and not from a fentanyl overdose. Much of what he testified supported Tobin's conclusions about Floyd's deteriorating condition and movements in his effort to keep breathing.

Smock said Floyd was not snoring, had dilated pupils, and was talking and saying "I can't breathe."

"That is not a fentanyl overdose," he said. "That is someone begging to breathe."

Smock testified that Floyd also showed no signs at the scene of a diagnosis called excitable delirium. He also addressed the need for CPR, "way before it was. As soon as Mr. Floyd was unconscious, he should have been rolled over. ... When they can't find a pulse, CPR should have been started."

1. Dr. Lindsey Thomas, a medical examiner of 37 years who retired from the Hennepin County Medical Examiner's Office and still works part-time as a forensic pathologist in Reno and Salt Lake City. She called the primary mechanism of Floyd's death asphyxia, or low oxygen. She said that the sheer volume of videos of Floyd's death was "absolutely unique" in that she'd never had a case so thoroughly documented, and it helped her arrive to determine how Floyd died.

"What I observed from all of these videos is this was not a sudden death," Thomas testified. "It's not like snow shoveling when someone clutches their chest and falls over. There was nothing sudden about his death."

She later said with certainty, "There's no evidence to suggest he would have died that night except for the interactions with law enforcement."

2. Dr. Andrew Baker, the chief Hennepin County Medical Examiner who performed Floyd's autopsy and stood by his ruling that Floyd's cause of death was a homicide, caused by "cardiopulmonary arrest complicating law enforcement subdual, restraint, and neck compression." Baker did not include a lack of oxygen, or asphyxia, a cause that three medical expert witnesses have firmly said was what killed Floyd.

The doctor tied Floyd's "very severe underlying heart disease" and enlarged heart, which needed more oxygen, combined with the stress of being pinned to the street with his face scraping the asphalt.

"Those events are gonna cause stress hormones to pour out of your body, specifically things like adrenaline, and what that adrenaline is going to do is it's going to ask your heart to beat faster," Baker testified.

"It's going to ask your body for more oxygen so that you can get through that altercation, and in my opinion, the law enforcement subdual restraint and the neck compression was just more than Mr. Floyd could take by virtue of those heart conditions."

1. Dr. Jonathan Rich, a cardiologist at Northwestern Memorial Hospital in Chicago, and associate professor of medicine at Northwestern University. He testified that Floyd's cause of death was "cardiopulmonary arrest caused by low oxygen levels and those low oxygen levels were induced by the prone restraint and positional asphyxia that he was subjected to." It was clear to him, he testified, that Floyd did not die because of a heart issue because his death was not sudden, nor did he die of an overdose. Repositioning him "very likely would have saved his life," Rich said.

"I believe that Mr. George Floyd's death was absolutely preventable," Rich testified.

2. Philonise Floyd, the younger brother of George Floyd, who served as the prosecution's "spark of life" witness. He described what it was like growing up in Houston with Floyd and his other siblings, playing video games and basketball. George was a mama's boy, he said, and although he hadn't seen Floyd in a couple of years, they spoke regularly on the phone.

"He was one of those people in the community when they had church outside, people would attend church just because he was there. Nobody would go out there until they seen him. He was a person everybody loved around the community, he just knew how to make people feel better."

3. Seth Stoughton, a University of South Carolina School of Law professor and former Tallahassee police officer who served as a use of force expert. He used the "reasonable officer" standard and testified that a handcuffed, non-aggressive Floyd did not constitute a threat to Chauvin, and his level of force was disproportionate. "No reasonable officer would have believed that this was an appropriate, acceptable or reasonable use of force."

"Looking at the threat analysis here, it's clear from the number of officers here and the fact that he's handcuffed and has been searched, he doesn't present a threat …Given the range of other alternatives available to the officers, it's just not appropriate to prone someone who is at that point cooperative."

1. Scott Creighton, a retired Minneapolis police officer who worked in narcotics, and testified about a May 2019 traffic stop during which he pointed his gun at Floyd because an agitated Floyd would not show his hands. Portions of the stop were shown to the jury through clips from Creighton's body camera.

"The passenger was unresponsive and noncompliant to my commands, I then had to physically reach in and I wanted to see his hands," Creighton testified. "In my mind his behavior was very nervous, anxious."

2. Michelle Moseng, a now retired paramedic with Hennepin EMS who was summoned to assist Floyd on the day he was detained in May 2019 at the Police Department's Fourth Precinct in north Minneapolis. Moseng said Floyd's blood pressure was extremely high, and she wanted him to go the hospital because she was concerned that he was at risk of a stroke. She said Floyd explained that "he had a history of hypertension and hadn't been taking his medication." Moseng acknowledged that Floyd was alert, obeying commands, and his respiration and pulse rates were normal. She said her records indicated he had taken about seven percocets.

"I asked why and he said it was because he was addicted," Moseng said.

3. Shawanda Hill, one of the passengers in the Mercedes SUV with Floyd. She and Floyd crossed paths at Cup Foods on May 25, and he appeared normal, and was talking and alert. But when they went to his SUV after he offered to give her a ride home, "he fell asleep," she said, in her first public statements about his friend's arrest, under defense questioning. When store employees approached the vehicle about Floyd passing a fake $20 bill, according to Hill, "they were trying to wake him up, trying to wake him up over and over. He woke up, he'll say something, made a little gesture and nodded back off." She added that Floyd told her "he was tired because he had been working." Hill said Floyd woke up the second time she tried to rouse him and told him, "'The police is here. It's about the $20 bill that wasn't real.'"

She testified that she went on to tell Floyd, "'Baby, that's the police. Roll down the window.' ... The man had a gun at the window. [Floyd] instantly grabbed the wheel, and he said, 'Please, please don't shoot me.'"

4. Peter Chang, a Minneapolis Park Police officer who was stationed at a nearby park when he responded to assist. When he arrived, Floyd was handcuffed and seated on the sidewalk. He was asked to run Floyd's information on the computer. He then returned to the squad car where Lane and Keung were struggling with Floyd. They told him instead to watch Floyd's SUV. People were at every corner of the intersection, he said, testifying earlier that the crowd was "very aggressive toward the officers, yes."

Chang said he then spoke with Shawanda Hill and Morries Hall and held them in place in front of Dragon Wok. Because of the placement of Chang's squad, none of them could see what was happening to Floyd, according to his body camera video of the incident.

5. Nicole Mackenzie, an MPD medical support coordinator who was also called as a prosecution witness. She was questioned about "excited delirium," a condition disputed among health professionals that is taught to MPD cadets.

Mackenzie said the training points out that the syndrome leads to psychotic behavior, agitation, incoherent speech, superhuman strength and hyperthermia. She said cadets are trained to have an ambulance stage at a safe distance from the scene where a suspect might be experiencing excited delirium. She said an ambulance is needed because a "suspect can rapidly go into cardiac arrest." Mackenzie said that CPR is also taught under this situation. Floyd was not given CPR on May 25 until after he was in an ambulance on the way to the hospital.

6. Barry Brodd, a use of force expert and retired police officer. He testified for the defense that he believed Chauvin's actions were reasonable.

"I felt that Derek Chauvin was justified and acting with objective reasonableness following MPD policy and current standards of law enforcement in his interactions with Mr. Floyd," he said.

When asked about his opinion, Brodd brought up a scenario he taught at the academy referring to a domestic violence incident where an individual is Tased, falls to ground and strikes his head. That's not deadly force, that's an accidental death, Brodd contended.

Brodd, who for served 22 years in the Santa Rosa Police Department before his retirement in 2004, said it's important for anyone "to try to see it as the officer on the scene ... then try to put yourself in the officer's shoes. It's easy to sit in an office and judge an officer's conduct."

Brodd testified that police used force in attempting to get Floyd in the squad and getting him to the ground, but once Floyd was on the ground, Brodd said he didn't believe the "prone control" position was use of force.

1. Dr. David Fowler, a former chief medical examiner who recently retired after 17 years working for the state of Maryland. Fowler served as an expert medical witness for the defense. He testified that George Floyd died of cardiac arrest combined with illicit drugs in his body and not from a lack of oxygen. He wrapped his testimony by saying he would have classified Floyd's manner of death as undetermined due to the multiple factors he cited.

Fowler said Floyd had a cardiac arrhythmia due to his heart disease while he was restrained by police, prone on the pavement at 38th and Chicago. The doctor said Floyd's fentanyl and methamphetamine use also played a significant role. He also included exposure to vehicle exhaust from a police squad close by his paraganglioma, tumors that can form near the carotid artery, and along nerve pathways in the head and neck.

"All of those combined to cause Mr. Floyd's death," Fowler said. He did not include lack of oxygen, or asphyxia, as the prosecution has contended.

What to expect next: Judge Peter Cahill said sentencing would take place in roughly eight weeks. Cahill will be asked to determine whether there were aggravating factors in the case, which the prosecution can use in arguing for a higher than recommended prison term. Former MPD officers Kueng, Lane and Thao are scheduled to be tried Aug. 23 for aiding and abetting second-degree murder and manslaughter in Floyd's death.