A grand jury on Tuesday returned indictments for engaging in organized criminal activity against 106 of the 177 bikers arrested following the deadly shootout outside a Waco, Texas, restaurant in May, the McLennan County district attorney said.

In a nine-hour session, the grand jury acted on all 106 cases that it had been asked to consider related to the shootout between police and bikers outside a Twin Peaks restaurant on May 17, District Attorney Abel Reyna said at a press conference Tuesday evening.

Reyna said the grand jury will return to consider charges against the other 71 bikers arrested on identical charges.

The next grand jury session is scheduled for Nov. 18, but Reyna declined to say if the rest of the cases will be presented then.

"We are not done," Reyna said. "We still have a lot of work to do. We will continue to do that. My office is dedicated, as is the team, to seeing that justice is done in all those cases."

Nine people died and 20 were injured during the shooting, which authorities say arose from an apparent confrontation between the Bandidos and the Cossacks motorcycle clubs.

More than 430 weapons were recovered from the crime scene, including 151 firearms. The gunfire erupted shortly before a meeting of a coalition of motorcycle clubs that advocates for rider safety.

Investigators have offered few details about what sparked the fight or how the gunfire played out. It remains unclear whose bullets struck those who died or were hurt, and no one has been charged in any of the deaths.

John Wilson, the president of the McLennan County Cossacks, and his son, Jacob Wilson, were both indicted Tuesday. Wilson said that he had "full confidence" neither he nor his son would be convicted and that he would refuse a plea bargain if offered.

The indictment "doesn't mean much," he said, adding he believes that since the indictments were done in such a short amount of time that they were "a cookie-cutter deal."

Six of San Antonio-based attorney Jay Norton's clients were indicted Tuesday. He said that based on the pretrial discovery materials he had reviewed in the case, there was a "serious lack of evidence" to indict 106 people.

"This is amazing and truly scary. We do not understand what the district attorney's office is doing, but it's not about reality," he said.

First Assistant District Attorney Michael Jarrett didn't respond to a request for comment late Tuesday night.

The last person held in connection with the shootout was released from jail last week. Like the others, he was initially held on a $1 million bond on charges of engaging in organized criminal activity. His bond was reduced to $50,000.