WACO, Texas -- Tuesday is the one year anniversary of the deadly Twin Peaks biker shootout in Waco.
Nine people were killed and 20 were injured after shots erupted between members of several motorcycle clubs.
Members of the Bandidos, Cossacks and other clubs gathered at the restaurant for a meeting about the political rights of bikers.
Waco Police and SWAT were outside the restaurant when the shooting started.
That's when officers also opened fire.
Authorities believe a turf war may have been a factor in the shootout.
According to the Associated Press, ballistics reports show four of the dead were shot by .223-caliber rifles, the only type of weapon fired by police. Two had wounds from only that kind of rifle; the other two were also struck by other guns. The five other bodies only had wounds from other guns.
It's not clear whether any bikers had .223-caliber rifles.
Although 20 people were treated for gunshot and other wounds sustained in the shootout, which began before a meeting of a coalition of motorcycle clubs that advocates rider safety, more people may have been injured.
Many witnesses, including bikers involved in the brawl and Twin Peaks waitresses, told police and Texas Rangers that the shooting began after a Bandido hit a prospective member of the Cossacks with his motorcycle, according to the evidence. A fistfight ensued, followed by several minutes of shooting.
Waco Police Chief Brent Stroman said in June that three officers fired a total of 12 shots, but police have not said whether the bullets struck anyone, fatally or otherwise.
In a surveillance video obtained by CNN, you can see people diving for cover and multiple gang members with guns -- even some bikers shooting.
MORE | Surveillance Video Shows Chaos of Waco Biker Gang Shootout
Following the shooting, 177 people were arrested and held for days or weeks on $1 million bonds on charges of engaging in organized criminal activity. But no formal charges have been made, and it remains unclear whose bullets struck the dead and injured.
Bikers were taken to the Waco convention center for processing after the shootout and were told on the way that they were going to be interviewed as witnesses, according to a 430-page Texas Department of Public Safety report that corroborates what arrested bikers have told AP. But the district attorney's office decided late that night to arrest the majority of those detained.
DA Abel Reyna and his staff told authorities at the convention center that if a person was wearing a patch, clothing or insignia that indicated support for the Bandidos or Cossacks, he or she should be charged with engaging in organized crime, according to the report. Reyna could not be reached for comment.
More than 430 weapons were recovered from the crime scene, including 151 firearms, according to the incident report. Many weapons were taken from bikers, while others were recovered from vehicles, bushes outside the restaurant and the men's bathroom, where two pistols were found in toilets, photos show.
Authorities "did not know exactly what to do with (the large number of weapons) and just started laying them on the ground away from the suspects," Officer Joshua Fischer wrote in the incident report.
After the shooting had ceased, an officer asked everyone with a weapon to raise a hand, according to the incident report. Nearly everyone did.