Editor's note: An earlier version of this story had an incorrect name for Reed's attorney.

The big question is not whether Tymon Reed fired the shots that killed Javon Reilly on Sept. 19, 2016. Rather, Reed's attorneys argue, the question is Reed's thought process, or lack thereof, behind the shooting.

Reed, 21, is charged with first-degree murder and armed criminal action in the shooting death of Reilly, 16, near Van Horn High School. The shooting happened during a confrontation near Truman Road and Home Avenue as Reilly and several other Van Horn students started to walk home.

The trial started Tuesday morning at the Eastern Jackson County Courthouse and is expected to end Wednesday. The jury will then deliberate on a sentence.

Reed's attorney, Molly Hastings, said the jury – which, with alternates, is nine women and five men – will have four options. They could find Reed guilty of first- or second-degree murder or voluntary or involuntary manslaughter.

In her opening argument, Hastings' co-counsel Sara Christensen said the case is about the details and whether Reed displayed the pre-meditation necessary for first-degree murder.

“There are very few facts that are in dispute,” she said. “Tymon Reed was there; he had a gun; he fired the gun; Javon Reilly died.”

Christensen said evidence will show no reflection on Reed's part. He and a friend went to the area of Van Horn looking to talk with someone about a previous incident in which Reed was robbed of marijuana at gunpoint. The meeting grew confrontational, though.

“He wanted to be done with it,” Christensen said. “He wanted to smooth it over, to move on.

“There was panic; there was fear; there was adrenaline.”

Assistant prosecutor Traci Stansell said that while Reed was waiting for Reilly and his friends, he wasn't specifically looking for Reilly.

“He wanted to know where somebody was, and Javon Reilly was going to tell him one way or another,” Stansell said.

Three other students who saw or heard the shooting testified for the prosecution. One of them, Ni'kia Porter, took a cell phone video thinking Reed and Reilly were going to have a fistfight.

“You hear multiple gunshots,” Stansell said during her opening statement. “Six of those gunshots ripped through Javon Reilly's body; five of them in his back.

“Those three witnessed something no child should ever have to see.”

Porter and Cesar Vazquez testified that they had never seen Reed and his friend before that day. Porter said that after Reilly handed her his backpack, she pulled out her phone thinking she would be filming a fight. The youngsters had started to walk north on Home Avenue – not forced, she said – until the third time Reed and Reilly were “squaring up” and Reilly said he wasn't going to walk any further.

At that point, she said, Reed pulled out a gun and pointed it at Reilly's feet, Reilly tried to get the gun out of his hands and Reed fired. Porter wasn't scared, she said, until the gun came out. Her video, played for the jury, showed Reed and Reilly moving around near each other, but when the gun appeared the phone's view turned away. Viewers then heard multiple gun shots.

“It escalated very quickly,” she said.

Vazquez said he could not hear what Reed and Reilly argued about, and he did not follow the group on Home Avenue, instead waiting on a bench for a ride home. When he saw Reilly take off his backpack, he said he gave Reilly a look of “What are you doing?”

Vazquez didn't see the shooting, he said, but heard the buildup.

Devyn Weeks, who was getting a ride home, walked across the street from the gas station when he saw the people on Home Avenue.

“To me, it seemed Javon didn't want to fight all that much,” he said. “I knew something was off the about the situation.”

Weeks said when Reilly told Reed he wasn't going to walk any further, Reed pulled out his gun and pointed it at Reilly's feet. Reilly then jumped back, Reed got closer and pointed toward Reed's stomach. Reilly then reached for the gun and they wrestled for a couple seconds, Weeks said, before Reed pulled the gun back.

Reilly then fell, got up and started running, and that's when Reed started shooting, Weeks said.

Weeks told police he recognized Reed from playing basketball with him at the YMCA in North Kansas City and had conversed with him on Snapchat. Reed had told him his name was “Derek,” which a police detective later testified was Reed's middle name.

Police used the Snapchat handle to identify Reed, they testified, and with information from Reed's mother were able to locate and arrest Reed at a convenience store near Interstate 29 and Barry Road in Platte County. Detective Loran Freeman testified that Reed appeared a bit surprised he was found, but he was arrested without incident.