Police were aware of the meeting in advance, and at least 12 Waco officers in addition to state troopers were outside the restaurant, part of a national chain that features scantily clad waitresses, when the fight began.
"We've been made aware in the past few months of rival biker gangs ... being here and causing issues," Swanton said.
Officers shot armed bikers, Swanton said, adding that the actions of law enforcement prevented further deaths. It was not known if any of the nine dead were killed by police officers.
Swanton said that the restaurant's operators also were aware of the meeting in advance, and he described the management as uncooperative with authorities in addressing concerns.
"Apparently the management (of Twin Peaks) wanted them here and so we didn't have any say-so on whether they could be here or not," Swanton said.