The lone survivor of the three people who were shot by Kyle Rittenhouse during unrest in Kenosha, Wisconsin, last year testified during Rittenhouse's trial this Monday.

Rittenhouse, who was 17 at the time, has said he wanted to help vigilante groups trying to protect the city of Kenosha following riots over a police shooting that left a Black man paralyzed.

Rittenhouse opened fire in confusing circumstances, killing two men, Joseph Rosenbaum and Anthony Huber, and badly wounding a third, Gaige Grosskreutz.

During his questioning by prosecutors, Grosskreutz acknowledged that he was carrying a handgun as he chased Rittenhouse while he was running towards police.

Rittenhouse ended up shooting and killing Anthony Huber after Huber lunged at him and tried to hit Rittenhouse over the head with a skateboard. During those seconds, Grosskreutz was shot in the arm by Rittenhouse.

Grosskreutz testified that after Huber was killed, he put in hands in the air as he saw Rittenhouse's AR-15 point towards him. He claimed that before he was shot, he saw Rittenhouse "re-rack" his weapon before firing.

"Re-racking the weapon, in my mind, meant that [Rittenhouse] pulled the trigger while my hands were in the air, but the gun didn't fire," Grosskreutz said. "So then by re-racking the weapon, I inferred that [Rittenhouse] wasn't accepting my surrender."

Arrested not long afterward, Rittenhouse was charged with five felony counts, including first-degree homicide, before being freed on bail of $2 million.

That large sum was quickly raised by supporters across the country, including a prominent Donald Trump backer, the pillow company executive Mike Lindell, as well as actor Ricky Schroder.

If convicted during the trial in Kenosha County Circuit Court, Rittenhouse faces a possible life sentence.

Watch the video below:

WATCH: Shooting survivor says Kyle Rittenhouse re-racked his rifle after he put his hands up

With additional reporting by AFP