MINNEAPOLIS — Former Officer Derek Chauvin was justified in pinning George Floyd to the ground because he kept struggling, a use-of-force expert testified for the defense Tuesday, contradicting a parade of authorities from both inside and outside the Minneapolis Police Department.

Taking the stand at Chauvin’s murder trial, Barry Brodd, a former Santa Rosa, Calif., officer, stoutly defended Chauvin’s actions, even as a prosecutor pounded away at the witness, banging the lectern at one point during cross-examination and growing incredulous when Brodd suggested Floyd was struggling because he wasn’t “resting comfortably” on the pavement.

“It’s easy to sit and judge ... an officer’s conduct,” Brodd testified. “It’s more of a challenge to, again, put yourself in the officer’s shoes to try to make an evaluation through what they’re feeling, what they’re sensing, the fear they have, and then make a determination.”

Also testifying was Minneapolis Park Police Officer Peter Chang, who helped at the scene that day. He said he saw a “crowd” growing across the street that “was becoming more loud and aggressive, a lot of yelling across the street.”

“Did that cause you any concern?” Nelson asked.

“Concern for the officers’ safety, yes,” Chang replied.

Nelson hasn’t said whether Chauvin will take the stand. Testifying could open him up to devastating cross-examination but could also give the jury the opportunity to see any remorse or sympathy he might feel.