Charges against security guard at Nashville bar increased for fatal attack on guest waiting for Uber

A Tennessee security guard who was arrested in March and accused of beating a man to death is now facing aggravated charges.

Bar patron Austin Turner, who was 25 at the time of the incident, died weeks after he was allegedly punched by security guard Richard Cornelius outside Tin Roof in downtown Nashville on Feb. 18 following an alleged altercation between him and the security guard, the Metropolitan Nashville Police Department said at the time.

Richard Cornelius, 36, was arrested March 1 and charged with aggravated assault, according to Davidson County online court records.

Cornelius, who has since been released on bail, is now facing an aggravated charge of aggravated assault resulting in death, according to an updated online court filing.

Ben Powers, Cornelius' attorney, had previously said in a statement to PEOPLE: “Mr. Cornelius is innocent of the charges in the indictment against him. And we can't wait to go to trial so we can address the misrepresentations surrounding the night in question. However, we will reserve further comment for our day in court.”

Powers now tells PEOPLE that his client plans to plead not guilty and claim self-defense, adding that “there is more to the story.”

“We stand by our earlier statement [that] “There's more to the story,” says Powers, “the incident happened off camera. The video shows the end of the altercation. There's more to the story than just the video.”

Surveillance footage of the incident shows Cornelius allegedly lashing out several times before hitting Turner, WSMV reported at the time, citing police.

MNPD authorities had previously stated that Cornelius allegedly hit Turner, “causing him to fall to the ground unconscious.”

Turner's family told PEOPLE in March that he was at the Tin Roof bar with his friends the night of the incident and that after they left the bar, he tried to go back inside, according to witnesses.

“We believe his phone was dead and he was looking for a way to charge it,” said his stepmother, Meagan Turner, adding that his Uber order was never fulfilled.

According to witnesses, he was not allowed back in and after being pushed through the entrance, he began to walk away, Meagan said.

“He didn't try to fight with anyone, he walked away from the entrance without any aggression or anything like that,” she added.

The witnesses then reportedly saw a man they believed to be the bouncer run toward Austin, “flailing wildly and then hitting Austin in the head,” Meagan reported.

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“He was unconscious and they said the sound they heard when he was hit … was very disturbing and they knew it was something bad,” she said.

“They are 100 percent claiming that Austin had his back turned the entire time during this incident,” Austin's father, Joshua Turner, told PEOPLE at the time.

A GoFundMe page set up by his family after the attack said he suffered a skull fracture that resulted in a subdural hematoma that required a craniotomy.

He later suffered five more strokes, the family said, before finally passing away on March 7. He was 26 when he was in a coma, WSMV reported at the time.

According to online court records, Cornelius is scheduled to go on trial in September.