Waco, Texas (CNN) After the guns fell silent on May 17 -- one of the bloodiest afternoons in the history of American motorcycle clubs -- nine bikers lay dead in a strip mall parking lot littered with weapons.

Many more were injured, bleeding from gunshots and knife wounds. A police officer asked what every other cop there must have wondered at that moment: How many of you are armed?

"I asked anybody who had a gun to raise their hand," Waco Officer Ryan Holt wrote in a police report obtained by CNN.

Nearly everybody did.

As Holt and his fellow officers disarmed the injured bikers, so many guns piled up on the ground that they literally got in the way. SWAT team officers drove a pickup truck to the crime scene "so we could pile the firearms in the bed to try to keep suspects from moving over the top of them," Holt noted in his report.

480 weapons, 177 arrests

In all, police recovered 480 weapons: 151 guns, along with assorted knives, brass knuckles, batons, hammers, and the bikers' blunt objects of choice -- padlocks wrapped in bandanas.

Some 177 bikers were arrested -- so many that they were taken to the Waco Convention Center and held for processing in separate rooms: one for members of the club known as the Bandidos and the other for their rivals, the Cossacks. All were jailed on $1 million bail each and charged with engaging in organized crime activity.

More than five months later, no one has been charged in the deaths of the nine bikers. Police and prosecutors are silenced by a gag order; a grand jury is weighing charges in the case.

After the shootout, 177 people were arrested.

But against a backdrop of official silence, CNN has obtained thousands of pages of documents -- including police intelligence reports, crime scene photos and witness interviews -- as well as surveillance video. These begin to tell the story of how a midday gunfight turned the parking lot of a Waco strip mall into a battle zone.

They also show that tension had been building for months between the two motorcycle clubs.

The oldest club in Texas versus the upstarts

The Bandidos, formed in Houston in 1966, are the oldest, largest and most powerful motorcycle group in Texas with more than 2,000 members, according to the Department of Justice. They have a national presence, particularly in Southern states. The Cossacks formed a few years later but kept a low profile. Now, they're considered an upstart, with about 800 members and, according to police, a strong desire to beef up their presence in their home state of Texas.

Although the bikers insist their clubs are social, even philanthropic organizations, police see both as criminal gangs. Law enforcement officials call them outlaw biker clubs, among the "one-percenters."

That label is derived from a quote that may be apocryphal but is part of biker lore that dates back to the 1960s: Someone supposedly said that 99% of bikers are law-abiding citizens, leaving the mayhem to the other one percent.

Both clubs deny they are involved in criminal activities such as drug distribution. They scoff at the notion that they are gangs in disguise. The Bandidos denied any wrongdoing in a news release after the gunfight. They accused police of mishandling the confrontation and giving the public "a false narrative."

"Members of the Bandidos were not aggressors, did not start the altercation, did not strike first, were not the first to pull weapons, and were not the first to use weapons," the club stated in its news release. "The majority of the Bandidos took cover, and all involvement in the altercation by members of the Bandidos was in self-defense."

What started it?

It's difficult to know for certain who started the mayhem on May 17. A review of the voluminous police file raises some troubling questions and intriguing theories. The witness accounts vary widely, depending on who's talking and what his or her club alliances might be.

Photos: Waco biker shootout: The crime scene On May 17, 2015, a fight broke out between two rival biker clubs in Waco, Texas. CNN has obtained video and images of the chaos during and after the brawl. This surveillance footage shows a biker running inside the Twin Peaks restaurant where the deadly fight took place. Authorities have classified both the Bandidos and the Cossacks as gangs. Hide Caption 1 of 36 Photos: Waco biker shootout: The crime scene Hide Caption 2 of 36 Photos: Waco biker shootout: The crime scene By the time the melee was over, nine people were dead and 177 people were arrested. Hide Caption 3 of 36 Photos: Waco biker shootout: The crime scene The body of a biker is seen in the parking lot. (His tattoos have been obscured in this photo.) The biker club members who began beating, stabbing and shooting each other in a Texas Twin Peaks restaurant knew the police were outside, and they just didn't care, Waco police Sgt. W. Patrick Swanton told CNN at the time. Hide Caption 4 of 36 Photos: Waco biker shootout: The crime scene A Bandidos vest and hat are left behind in a pool of blood. The Bandidos boast a membership of 2,000 to 2,500 across not just the United States, but also 13 other countries, the Department of Justice says. Hide Caption 5 of 36 Photos: Waco biker shootout: The crime scene Law enforcement agents received information that a regular scheduled meeting of the United Coalition of Clubs was to be held at a Twin Peaks restaurant in Waco on May 17. Due to the known growing tension between the Bandidos and the Cossacks, the Waco Police Department coordinated a surveillance and intelligence-gathering operation for this meeting, according to documents from the Waco Police Department and the Texas Department of Public Safety. Hide Caption 6 of 36 Photos: Waco biker shootout: The crime scene Another body lies next to a tipped-over bike. Police officers fired 12 rounds during the deadly shootout, according to the Waco Police Department, which said it had 16 uniformed officers in their vehicles at the time the suspects began shooting. Hide Caption 7 of 36 Photos: Waco biker shootout: The crime scene This violent encounter wasn't the first between the Cossacks and the Bandidos, according to a Waco PD investigator's sworn statement. Members of both motorcycle clubs had previous violent altercations throughout Texas in 2013 and 2015. Several of those involved were arrested at the Waco brawl. Hide Caption 8 of 36 Photos: Waco biker shootout: The crime scene According to a Waco PD investigator's sworn statement, Waco police witnessed the violence erupt that day "swiftly" and law enforcement officers on the scene were fired upon by "individuals involved in the violent altercation" until officers were able to control the scene. Hide Caption 9 of 36 Photos: Waco biker shootout: The crime scene According to witness statements given to Waco Police by a Twin Peaks patron: "Just as we had finished eating I heard 5, 6, or 7 shots from outside of the restaurant. Someone yelled hit the floor, there was constant shots being fired. It sounded like the gunfight at the OK Corral. " Hide Caption 10 of 36 Photos: Waco biker shootout: The crime scene Weapons were found all over the scene, including this gun in the bathroom. Hide Caption 11 of 36 Photos: Waco biker shootout: The crime scene The Waco PD says about 480 weapons were found that day. Hide Caption 12 of 36 Photos: Waco biker shootout: The crime scene Police also recovered an ax, bats, batons, brass knuckles, a chain, clubs, a hatchet, knives, a machete, pepper spray, a pipe, stun guns, tomahawks and weighted weapons. Hide Caption 13 of 36 Photos: Waco biker shootout: The crime scene Police recovered many knives from the scene. Hide Caption 14 of 36 Photos: Waco biker shootout: The crime scene Twelve long guns and 133 handguns were recovered. Hide Caption 15 of 36 Photos: Waco biker shootout: The crime scene A gun is seen in the passenger seat of a car. Hide Caption 16 of 36 Photos: Waco biker shootout: The crime scene Waco PD said that 44 shell casings were recovered from the scene and that 12 of those casings came from the .223-caliber rifles of three SWAT officers, who were in adjacent parking lots.

Hide Caption 17 of 36 Photos: Waco biker shootout: The crime scene This is one of the many weapons recovered. Hide Caption 18 of 36 Photos: Waco biker shootout: The crime scene A gun is inside a motorcycle saddlebag, along with prescription medicine and a water bottle. Hide Caption 19 of 36 Photos: Waco biker shootout: The crime scene Hide Caption 20 of 36 Photos: Waco biker shootout: The crime scene Tensions between the Cossacks and Bandidos had been on the rise for a while. Hide Caption 21 of 36 Photos: Waco biker shootout: The crime scene According to witness statements given to police, a Twin Peaks employee said that prior to the fight that led to the shooting, the Cossacks were attempting to keep their conversation private. "Every time a Twin Peaks girl would go outside they (Cossacks) would get extremely quiet and when we would go back inside they would continue to talk." Hide Caption 22 of 36 Photos: Waco biker shootout: The crime scene The fight broke out at the Twin Peaks restaurant and spilled into the parking lot. The weapons being used quickly escalated from hands and feet to guns. Hide Caption 23 of 36 Photos: Waco biker shootout: The crime scene Weapons are piled up by a barrier in the parking lot. According to one of the first Waco police officers on the scene, it appeared that nearly everybody in the crowd had a gun. Hide Caption 24 of 36 Photos: Waco biker shootout: The crime scene Sixteen uniformed Waco Police Department officers, including members of their SWAT team, witnessed and responded to the melee from the parking lots surrounding Twin Peaks. Police say they responded within 30 to 45 seconds and were fired at by bikers. Hide Caption 25 of 36 Photos: Waco biker shootout: The crime scene Jewelry lies on the asphalt in the Twin Peaks parking lot. The label is derived from a quote that may be apocryphal but is part of biker lore that dates to the 1960s: Someone supposedly said that 99% of bikers are law-abiding citizens, leaving the mayhem to the other 1%. Hide Caption 26 of 36 Photos: Waco biker shootout: The crime scene Seven of the nine bikers who were killed at Twin Peaks were members of the Cossacks. The Cossacks claim around 200 members, mostly in small towns in Texas. According to law enforcement officials, they are one of the biggest outlaw biker clubs in Texas. Hide Caption 27 of 36 Photos: Waco biker shootout: The crime scene This is one of the Bandidos patches from the thousands of evidence photos taken from Twin Peaks. The Bandidos are the biggest motorcycle clubs in Texas, with around 400 members. Hide Caption 28 of 36 Photos: Waco biker shootout: The crime scene An officer from the Waco Police Department discovered blood smeared across the Twin Peaks bathroom floor. Hide Caption 29 of 36 Photos: Waco biker shootout: The crime scene One of the 151 guns found by investigators was in the grass outside Twin Peaks after the fight. Police recovered a staggering 480 weapons from Twin Peaks: 151 guns, numerous knives, brass knuckles, chains, clubs, batons, hammers, tomahawks and a machete. Hide Caption 30 of 36 Photos: Waco biker shootout: The crime scene A Cossacks jacket, along with knives and a gun, litter the grass outside Twin Peaks after the melee. There were 154 bikers indicted by a Waco grand jury, and they could face life in prison on charges of engaging in organized criminal activity. Hide Caption 31 of 36 Photos: Waco biker shootout: The crime scene A bloody bandana lies on the sidewalk outside of Twin Peaks. Both clubs, the Bandidos and the Cossacks, say they're done fighting. Hide Caption 32 of 36 Photos: Waco biker shootout: The crime scene A Waco police officer snapped this photo after he discovered blood spilling out onto the sink and floor in the Twin Peaks bathroom. Hide Caption 33 of 36 Photos: Waco biker shootout: The crime scene These are some of the bullets found on the scene by investigators. According to the Waco Police Department, 44 shell casings recovered from the Twin Peaks scene were fired by law enforcement weapons. Hide Caption 34 of 36 Photos: Waco biker shootout: The crime scene A duffel bag is filled with patches of the Confederation Of Clubs & Coalition of Independent Riders. COCs are biker networks that exist in nearly every U.S. state and meet every couple of months or so to discuss motorcycle issues and legislation. A 1 p.m. COC meeting was scheduled to take place at Twin Peaks on May 17. Hide Caption 35 of 36 Photos: Waco biker shootout: The crime scene Knives and weapons are thrown across the dirt and weeds in the Twin Peaks parking lot. Hide Caption 36 of 36

The Bandidos had reserved the patio of the Twin Peaks restaurant for a meeting to discuss club business. They told police the Cossacks crashed the meeting, according to the incident report.

But many Cossacks and their supporters said they were invited to the meeting and told it had been called to broker peace. Now they're wondering if they were set up.

Harsh words were exchanged as the Bandidos rolled up to the restaurant to find a line of Cossack bikes already parked out front. Several witnesses insist that a high-ranking Bandido, backing his motorcycle into a parking space, struck a Cossack "prospect."

"The lead guy, I looked out -- I was watching -- he deliberately steered into one of our prospects and hit him," said John Wilson, president of the Waco-area chapter of the Cossacks. Wilson, who owns a Waco bike shop, Legends Cycles, spoke on camera with CNN.

He said he was unarmed and hadn't come to fight that day.

By his account, the Bandido biker "deliberately ran into" the Cossack prospect, hitting him hard enough to "knock him down." He described the prospect as "an older guy" with a leg brace who "certainly wasn't a threat to anybody."

Prospects are would-be members who are assigned menial tasks as they work their way up to becoming full-fledged, "patched" members. In this case, prospect Clifford Pearce was tasked with watching over the parked Cossack motorcycles.

Pearce insisted to police that nobody ran over his foot, as Wilson and some other witnesses claimed. But Pearce acknowledged that it might have looked like he'd been hit because he didn't move out of the way quickly enough. During the melee, he was shot in the spine and paralyzed. He declined to speak with CNN. Pearce has not been charged.

'It was pretty horrific'

Wilson said it didn't take long for harsh words to turn into flying fists, and finally gunshots.

"I couldn't even see who threw the punch," he told CNN. "But I saw our guy's head go back, and it looked like he was getting ready to punch back whoever did it and a shot went off." He heard "a couple more shots, some scuffling around and then, almost instantly, gunfire just erupted from all around the perimeter."

The view from Wilson's vantage point was heart-stopping.

"I promptly got down on that sidewalk trying to avoid being hit myself," he told CNN. "At that time it was pretty horrific, there were guys getting hit, falling, and I realized that I needed to get away from where I was. I looked to the guy to my left, a good friend of mine, and said, 'We need to get off the sidewalk or we are going to die here.'"

Other bikers were thinking the same thing. A large group ran from the gunfire toward Waco police Officer George Vrail as he stepped out of his patrol car. He ordered them to the ground; some said they'd been hit. The shooter, they said, fled into the bathroom.

Inside the men's room, officers found pools of blood, along with piles of bloody paper towels. It looked like an injured biker had tried to treat his wounds there. Whoever it was, he was gone.

Two fellow officers told Vrail they'd been shot at and returned fire. One, Heath Jackson, said he believed they'd both "struck multiple suspects." A third officer also told Vrail that he had "engaged with his weapon."

There has been no official word on whether anyone was injured or killed by police bullets.

'Streaks of blood, droplets and pools of blood'

Officer Kristina Woodruff was called to the scene on her day off. When she arrived at Twin Peaks, the food on the tables was still fresh, the drink glasses dewy with moisture, she recalled in a vividly written report.

She stepped around the bodies and walked across the patio.

"The music was blaring loudly and dead bikers were lying on the concrete, many of them with drying, coagulating blood turning from red to brown that gravitated to the crevices and cracks," Woodruff wrote. "There were streaks of blood, droplets and pools of blood, blood smearing and smudging all around."

And then there were the weapons.

"There were so many guns, knives and brass knuckles lying all around the motorcycles," she added in her report.

"It was unbelievable. They were everywhere."

These are some of the weapons police recovered.

The video, taken from more than a dozen surveillance cameras, reveals a chaotic scene inside the restaurant.

As the Bandido bikers roll into the parking lot, a crowd of Cassocks already gathered on the patio is eating and drinking; some are still being served.

The parking lot can't be seen on the video, but it does show the reaction of the Cossacks and their supporters.

Several men draw handguns. One biker runs across the patio, firing a gun wildly toward the crowd. A camera catches a small group of bikers, off to one side, pummeling a man.

Another camera angle shows a man running from the parking lot onto the patio. His face is a bloody pulp.

Some bikers leap over a patio fence and rush toward the parking lot -- and presumably into the gunfire. But nearly as many others run inside to hide in the restrooms and kitchen. They emerge under police escort, their hands held high in the air.

CNN also spoke with attorneys for some of the bikers charged with engaging in organized criminal activity. Some spent days or weeks in jail, unable to raise the required $1 million bail. They say their only mistake was being in the wrong place at the wrong time.

Turf and respect

While the initial fisticuffs might have been triggered by a perceived slight, police reports show the Bandidos and Cossacks had been locking horns for months over issues near and dear to any biker -- territory and respect.

The Bandidos decide what other groups can operate in Texas and charge them dues. They insist that only dues-paying members can wear a "Texas" patch on their jackets or vests, according to police documents.

Wilson, who heads the Waco-area Cossacks chapter, says the Bandidos are simply taking money from the other clubs. The Cossacks won't pay, he told police. After the shootout, the Bandidos released a statement calling the violence "senseless, unnecessary and wrong."

Yet Cossacks have been spotted wearing Texas patches even as they refuse to acknowledge the Bandidos' self-proclaimed supremacy. The Cossacks think they're being picked on. They consider the Bandidos to be "the bully on the block," as biker Robert "Vegas" Bucy told police.

Investigators were hearing about rising tension between the two clubs as early as March, according to a 430-page investigative report by the Texas Department of Public Safety. It is included among the documents CNN obtained.

Less than three weeks before the melee in Waco, the department issued a memo that warned of escalating violence between Bandidos and Cossacks, "with no indication of diminishing."

Warning signs

The memo, shared with law enforcement agencies across the state, cited clashes between the two clubs dating back to November 2013, when a Bandidos member was arrested after allegedly stabbing two Cossacks outside a restaurant in Abilene. Bandidos reportedly had knocked over and damaged the Cossacks' bikes in the parking lot, sparking a fight.

Two biker confrontations in March -- two months before the shootout in Waco -- caught the eye of police. Eight to 10 Cossacks forced a lone Bandido biker off the road. Police say they beat him with chains, batons and metal pipes. The same day, a group of Bandidos confronted a Cossack at a truck stop. They hit him over the head with a hammer, police said, after he refused to remove his "Texas" patch from the back of his vest. The Bandidos took the vest.

FBI agents in San Antonio and El Paso picked up intelligence that the Bandidos were planning to go to war with the Cossacks, and police were on alert during the spring biker rallies in Amarillo, Midland and Odessa. But nothing happened.

The Bandidos made a crucial decision on March 27 of this year, moving the regular meeting of the Confederation of Clubs and Independents from Austin to the Twin Peaks restaurant in Waco. Some considered that a direct challenge to the Cossacks, who frequented Twin Peaks' weekly Biker Nights and believed Waco to be "Cossack country."

Waco police feared, with good cause as it turned out, that the May 17 meeting would trigger violence. But the restaurant's manager complained to the police chief that the presence of cops scared away paying customers, according to police. Police had been asked to leave there on at least two occasions. So when undercover officers saw the crowd of Cossacks on the patio May 17, a decision was made to keep an eye on the place from outside.

They watched from the parking lot.

The gunbattle lasted just a couple of minutes.

Daniel Raymond "Diesel" Boyett, 44, was shot in the head.

Wayne Lee "Sidetrack" Campbell, 43, was shot in the head and torso.

Richard Matthew "Chain" Jordan III, 31, was shot in the head.

Richard Vincent "Bear" Kirschner Jr., 47, died of multiple gunshot wounds.

Jacob Lee Rhyne, 39, was shot in the neck.

Jesus Delgado Rodriguez, 65, who was unaffiliated with a club, was shot in the head and torso.

Charles Wayne "Dog" Russell, 46, was shot in the chest.

Matthew Mark Smith, 27, was shot in the torso.

Manuel Issac "Candyman" Rodriguez, 40, died of unspecified gunshot wounds. He was a Bandido.

The Cossacks lost seven "brothers." The Bandidos, one.