In what circumstances will a prosecution expert testify in a civil case about excessive force?

avoid the question of excessive force altogether by conflating it with whether the officers did as they were trained to do." ( People v. Brown , supra , 245 Cal.App.4th at p. 169, 199 Cal.Rptr.3d 303.) In contrast, Sibrian held a prosecution expert properly testified about an officer's need to escalate force when confronted with a noncompliant person and about "the potential continued danger posed by a suspect after he has been wrestled to the ground" and "the risks of allowing a noncompliant suspect to remain in his car and why the officers may have decided not to use a chemical agent." ( Sibrian , at p. 134, 207 Cal.Rptr.3d 428.) These points may have been helpful to the jury, as matters beyond the common understanding of lay persons. ( Id . at pp. 134-135, 207 Cal.Rptr.3d 428.)