EXPLAINER: Courtroom technology on display in Chauvin trial

CHICAGO (AP) — The foundation of the case against the former Minneapolis police officer charged with killing George Floyd is a mountain of video evidence, but presenting that to jurors isn't as easy as pushing play.

Over and over, prosecutors have shown video from surveillance cameras, bystanders’ cellphones and police body and dash cameras, and have asked witnesses to annotate footage or photographs and narrate the action on screen.

Large screens or projectors are fixtures of modern courtrooms, alongside software similar to PowerPoint designed for courtroom presentation of videos, photos and other evidence. But the quality of that technology and attorneys' use of it varies.

WHAT'S IN THE COURTROOM?

The courtroom being used for Derek Chauvin 's trial is the largest and only one in the Hennepin County courthouse equipped with the tools to present and annotate video and other visual evidence.

Jurors are able to see evidence on three monitors.

A touchscreen monitor is positioned at the witness stand. Prosecutors have been asking witnesses to circle themselves or point out details using a stylus.

Hennepin County Judge Peter Cahill has a monitor at his bench, and he's able to control when a witness’ annotations are visible to the courtroom.

Prosecutors have played dozens of video clips from bystanders' cellphones, the cameras Chauvin and other officers wore, and surveillance cameras on the street and inside the neighborhood store where Floyd was suspected of passing a counterfeit $20 bill.

They have used a picture-in-picture feature to play cellphone videos of Floyd and the officers beside an uninterrupted feed of the street from a surveillance camera, giving jurors a view from multiple perspectives and clarifying the context of the bystander videos.

The defense has...