A jailed suspect in the fatal shootings at a Juneteenth celebration in Round Rock has been charged with two counts of murder and 13 counts of aggravated assault with a deadly weapon, police said.

Keshawn Dixon, 18, is being held at the Williamson County Jail after being arrested July 6 in Killeen and initially charged with deadly conduct related to the shooting at Old Settlers Park on June 15.

The stage remains at Old Settlers Park in Round Rock on June 17 after two people were killed two nights before in a shooting during a Juneteenth celebration. On Friday, police charged one suspect with two counts of murder.

Round Rock police said in a statement late Friday announcing the new charges that the investigation remains ongoing.

Ricky Thompson III, 18, a student at Manor Senior High School, and a juvenile male were arrested within days of each other, with Thompson facing one charge of aggravated assault with a deadly weapon. Dixon was the third suspect arrested in the incident.

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Police have said an argument between two groups attending the Juneteenth event resulted in several people pulling out guns and shooting at one another about 10:50 p.m.

Lyndsey Vicknair, 33, of Manor and Ara Duke, 54, of Pflugerville were fatally shot. Police said Vicknair and Duke had been attending the celebration and were not associated with the altercation that preceded the shooting. Both victims were declared dead at the scene.

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According to his arrest affidavit, Dixon was seen firing at Thompson in the vending area of the Juneteenth celebration.

The altercation started because Thompson’s rap group, called Whaa Ent, had insulted Dixon’s rap group, Get Money Entertainment, the affidavit said.

“The disrespect revolved around a member of Get Money Entertainment who had been previously murdered,” police said.

Keshawn Dixon was seen firing his gun multiple times at the deadly Juneteenth celebration in Round Rock, an arrest affidavit said.

Dixon has a criminal history that includes arrests for three robberies, a terroristic threat, assault and evading arrest, police said. Get Money Entertainment is also a gang, according to the affidavit. Dixon’s most recent arrest in March was for unlawful carrying of a weapon and discharging a weapon in certain municipalities, the affidavit said.

More:Police: Deadly Round Rock Juneteenth shooting was dispute between rival rap groups

A witness to the Round Rock shooting said Dixon’s handgun was equipped with a switch that can convert the gun from a semi-automatic pistol to one that fires automatically, the affidavit said.