There's a look of calm on Oklahoma Highway Patrol Trooper Brian Costanza's face as he reaches into his backseat and grabs his AR-15 rifle and presses on the accelerator. Costanza's eyes are focused on the farm truck tearing down a dark country road ahead of him as he readies his weapon and begins to fire through his own windshield. By now many Oklahomans have seen the dashcam footage of Costanza chasing down Michael Vance, who during an 8-day October manhunt killed two family members, wounded three lawmen, and a motorist during an attempted carjacking. And while the video shows the last moments of Vance's life and offers a close-up view of one of the men who ended it, it only hints at the years of training and discipline that led up to that now infamous gunfight. “You don't rise to the occasion; you fall to your training,” Costanza said while standing on a jujitsu mat in a private gym just east of downtown Okmulgee. Costanza trains here most days with fellow troopers and young men interested in jujitsu. He likes the methodical nature of the sport, which just moments before had him locked arm and arm, leg to leg with another trooper, their faces bright red in the brief moments of pause before one of them tries to gain a dominant position over the other. Rigorous, daily training, Costanza said, can be the difference between him and a fugitive killer like Vance. “Some officers put on that gun and badge and they think they know it all,” Costanza said, a police scanner on a nearby table echoing through the small building. “If you have that mindset of ‘I know everything, I don't need to learn anything else,' then you're going to get left behind. Unfortunately, in our line of work that can mean death.” He looks over at two men grappling on the mat a few feet from him and smiles. “This mat will humble you.” Costanza is one of the lucky ones who pretty much always knew what he wanted to be when he grew up. It was a chance meeting with a state trooper as a young child that solidified his commitment to becoming an officer himself. A highway patrolman responded to a wreck involving one of his family's horses, and Costanza said he will never forget seeing the trooper walk through their stables. “He had his hat on and everything like that, and I was just amazed, infatuated,” Costanza said. After a year on the Okmulgee police department, Costanza made it through the trooper academy and joined the patrol in 2002. He's been on the highway patrol's tactical team, which responds to elevated threats, since 2006. Costanza carries himself with a natural confidence that belies his belief in constant self-assessment and preparation. He trains daily, eats well, and studies case law that deals with lethal force, which is what he and his colleagues on the tactical team were discussing the day before they ended Vance's life. “As we're talking around this deal, that was one of the things we were talking about,” Costanza said as he patrolled Okmulgee on a crisp January afternoon. “I know I've got a double murderer in front of me who at that time had already shot two cops and an innocent civilian at a carjacking, is it reasonable to believe that if I let him get away that he's going to leave and hurt more people?” Costanza left Okmulgee sometime after 9 p.m. on the night of October 30, hoping to be far enough west to provide assistance if Vance was spotted. Vance shot and wounded Dewey County Sheriff Clay Sander that evening, and Costanza soon found himself leading the chase. After Costanza fired a hole through his windshield, he carefully squeezed off several rounds, which can be seen in night vision footage captured from a helicopter, bursting off the headache rack of Vance's stolen farm truck. “After the very first round, I said to myself ‘It's really loud in here. ' It was absolutely deafening. I kept firing, and it was just ringing and I couldn't even understand what was going on (over) the radio.” Later that evening, his ears still filled with a piercing ring, Costanza would notice that the heat from his rifle had melted his dashboard. That, coupled with the 11 bullet holes Vance left in Costanza's Tahoe, would cause the department to decommission the patrol unit. Vance was nearing another roadblock ahead, and Costanza was focused on ending the threat. “When I started shooting I was hoping I was going to kill him,” he said. “That was my full intention. I want to end him right this second, because if I don't, if I can't get him to stop, then he's going to go down the road and he's going to have the ability to engage my partners at this next roadblock and there's a high probability one of them is going to have serious bodily injury or death.” After stopping and letting the farm truck slowly idle in reverse, Vance stood in front of the truck as it crept toward a line of officers and fired his AK-47. “I wanted to get out of this vehicle, because it was a coffin,” Costanza said. Costanza stepped out of his patrol unit, and he and his colleagues opened fire. Vance's figure can be seen in the helicopter's footage hitting the pavement.