ST. PAUL, Minn. (AP) — A former Minneapolis police officer charged in George Floyd’s killing testified Thursday that he didn’t act on another officer’s suggestion to roll Floyd on his side after he stopped breathing, didn’t ask Officer Derek Chauvin to check for a neck pulse and didn’t try to get Chauvin off Floyd’s neck.

J. Alexander Kueng is one of three former officers charged in federal court with violating Floyd’s constitutional rights when Chauvin pressed his knee into Floyd’s neck for 9 1/2 minutes as the 46-year-old Black man was handcuffed facedown on the street and pleading for air before going silent. Kueng knelt on Floyd’s back, Thomas Lane held his legs and Tou Thao kept bystanders back.

Prosecutor Manda Sertich peppered Kueng with questions about his training, including on material from an emergency medical responder course he took that said someone might not be breathing adequately even though they’re talking and then lists thing to check for.

She pointed out that Floyd stopped talking after about 4 ½ minutes and asked if it was a “red flag.”

“It is something to reassess, yes ma’am,” replied Kueng, who later agreed that he was trained to roll someone on their side to help them breathe when it was safe to do so.

But Kueng said he didn’t do so at Lane’s suggestion after Floyd passed out, or in the five minutes that officers kept him restrained afterward. Kueng said he checked Floyd’s wrist pulse twice and couldn’t find one, then told Chauvin, but didn’t try to check Floyd’s neck pulse himself.

All three officers are accused of depriving Floyd of his right to medical care. Prosecutors have argued that the officers violated their training by not rolling Floyd onto his side or giving him CPR.

Kueng and Thao are also accused of failing to intervene to stop Chauvin in the May 25, 2020, killing that triggered protests worldwide and a reexamination of racism and policing.

Defense attorneys contend the Minneapolis Police Department provided inadequate training and taught cadets and rookies to obey superiors. They have also said that Chauvin, who was convicted of state murder and manslaughter charges last year, called the shots that day.

A use-of-force expert testified that Kueng used “very minimal” force on Floyd and that holding and stabilizing him for the ambulance was proper.

Steve Ijames, a use-of-force instructor who retired as assistant police chief in Springfield, Missouri, also said the Minneapolis Police Department’s training on an officer’s duty to intervene to stop other officers from using excessive force was ineffective because it relied too heavily on lectures instead of hands-on training and testing to ensure that trainees learn the right lessons.

Kueng testified Wednesday that he deferred to Chauvin because he was his senior officer and that’s what he was trained to do. Kueng and Lane were both rookies, with just a few days working without a trainer. He also said it was up to Chauvin to check Floyd’s neck for a more accurate pulse and to make decisions on the “difficult balance between scene safety and medical care.”

“He was my senior officer and I trusted his advice,” said Kueng, who has said he feared he could be fired for disobeying a superior.

Thao testified this week that he relied on the other three officers on the scene to care for Floyd’s medical needs while he controlled the crowd and traffic and that he didn’t think Chauvin’s knee was on Floyd’s trachea.

Lane is also expected to testify.

Lane, who is white; Kueng, who is Black; and Thao, who is Hmong American, also face a separate state trial in June on charges alleging that they aided and abetted murder and manslaughter.

Chauvin, who is white, pleaded guilty in December to a federal civil rights charge.