ROUND ROCK, Texas —
A third suspect arrested in the Round Rock mass shooting may have lost control of his gun while using a machine gun conversion device.
Court documents obtained by KVUE reveal 18-year-old Keshawn Dixon is a documented gang member with an "extensive history" with Round Rock police. Dixon is the latest person to be arrested in the deadly shooting at the Juneteenth festival at Old Settlers Park.
According to the affidavit, Dixon told authorities he was only at the festival before the shooting that left two women dead and 14 others hurt.
Witnesses stated that they recognized Dixon even though he was wearing a white ski mask and a gray hoodie. One of Dixon's family members also allegedly admitted to a witness that he was involved in the shooting.
During their investigation, authorities learned that Dixon has a history of violent offenses, including terroristic threat, assault, evading arrest and multiple robberies. The affidavit states that Dixon also had pictures of himself on his Instagram holding a handgun with a "Glock switch," which can turn semi-automatic pistols and rifles into fully automatic weapons.
What happened at Old Settlers Park?
According to the affidavit, Dixon got into a fight with 17-year-old Ricky Thompson III, who has also been charged in the shooting.
The two allegedly fought over an ongoing rap feud between their two groups after Thompson's group disrespected someone from Dixon's group who was murdered.
A witness stated Dixon and Thompson "pulled out guns and started shooting" after a physical altercation when they confronted each other. The witness also said Dixon "fired the switch" and lost control of the gun.
The two women killed in the shooting were innocent bystanders, according to police, but it remains unclear who they were shot by. The other injured victims' ages range from 10 to 62 years old.
Dixon was arrested in Killeen and is now in the Williamson County Jail on a deadly conduct charge. Police say other charges are also possible. Dixon also admitted to police that he was in the area of the shooting when it happened.
Firearms expert Michael Cargill shared his take on the situation.
"The first thing that comes to mind is the fact that this young man used a Glock with a switch on it to try to shoot someone. Only an idiot would do something like that. It's very unstable. And No. 1 and No. 2, it's illegal to actually have one, to be in possession of one," Cargill said. "What makes them dangerous is the fact that people that are untrained, that are not trained with shooting guns at all and they're shooting a firearm, putting a device on it that actually turns it into an automatic. If you're not smart enough to be able to handle a firearm in the first place, when it's a semi-automatic, you're not going to be smart enough to handle it when it's an automatic."
Who else was arrested?
Thompson was the first person to be arrested in the shooting and faces a charge of aggravated assault.
Police say Thompson, a Manor ISD student, admitted to firing three shots at another person during the event. He was arrested in Pflugerville on June 20.
A second juvenile suspect was arrested on June 21, but little is known about his role in the shooting. Police said he was arrested and taken to the Williamson County Juvenile Justice Center.
Who were the victims?
Ara Duke and Lyndsey Vicknair were identified as the women killed during the festival shooting.
Duke was an administrator and founding staffer at IDEA Rundberg in North Austin. She was killed while attending the festival with her husband, Christopher.
Vicknair, a mother of three from Manor, was a member of the Austin Bar Association and a co-founder of the Austin Honey Badgers Track Club. She was also killed while attending the festival with her husband, Kevin.