The second trial of a police officer in the death of Elijah McClain begins Friday, one day after a Colorado jury convicted one officer and acquitted another in the 23-year-old unarmed Black man’s fatal encounter with Aurora police in 2019. McClain’s death galvanized protests against police brutality and racial injustice that swept the country in 2020 and spurred state and local policy changes for the kind of chokehold restraints and ketamine injections used during his arrest.