Memphis police officers are facing state charges including second-degree murder and aggravated assault in the beating death of Tyre Nichols.

Day four of the Tyre Nichols state trial began with the defense calling more witnesses. Preston Hemphill, a former officer, was first on the stand.

Testimony in the trial of three former Memphis officers charged with fatally beating Tyre Nichols resumes Wednesday, a day after defense attorneys sought to chip away at accusations that the officers used unnecessary force to subdue Nichols after he ran from a traffic stop.