Unlike any American before him, Chris Kyle performed his job with pinpoint accuracy. As a sharpshooter serving in Iraq, that job had deadly results. The Pentagon has credited Kyle with over 160 kills. The actual number could be almost double.

The most lethal sniper in American history was the son of a church deacon and a Sunday-school teacher. Growing up in Texas, Kyle hunted with his father and brother. After two years of college and working as a ranch hand, the 24-year-old Kyle quit school and joined the elite Navy SEALs—although he hated water. “If I see a puddle,” he told Time magazine, “I will walk around it.”

After serving in a number of classified missions, Kyle was deployed with members of platoon “Charlie” of SEAL Team 3 to fight in the Iraq War. After landing on the al-Faw Peninsula at the war’s outset in March 2003, the SEALs joined the Marines on their march north toward the capital city of Baghdad. Stationed on rooftops, Kyle and his fellow SEALs protected Marines squads going door to door from insurgent ambushes.

After entering the city of Nasiriya in the war’s early days, Kyle stationed himself atop a building seized by the SEALs. Through the scope of a bolt-action .300 Winchester Magnum, Kyle watched as a Marine convoy approached. Fifty yards away, he suddenly saw the door of a small house open and a woman step outside with her child. As she neared the Marines, Kyle watched through the crosshairs as the woman reached beneath her robe and pulled out a yellow grenade.

“Take a shot,” ordered Kyle’s platoon chief.

Kyle hesitated as the Marines continued to march closer.

“Shoot!” cried the chief.

Kyle squeezed the trigger twice. The woman fell dead to the ground along with the exploding grenade, which did no harm to the Marines. It was Kyle’s first kill with a sniper rifle. Many more deadly shots would be fired, but the hesitation would never return.

“It was my duty to shoot, and I don’t regret it. The woman was already dead. I was just making sure she didn’t take any Marines with her,” Kyle wrote in his 2012 combat memoir, “American Sniper: The Autobiography of the Most Lethal Sniper in U.S. Military History.”

Kyle’s sole mission in Iraq was to save his fellow servicemen, and he proved to be such a deadly sniper that Iraqi insurgents placed a $20,000 bounty on the head of the man they called “Al-Shaitan Ramad,” or “the Devil of Ramadi.” To Kyle’s fellow soldiers, however, he was known as “The Legend.”

The 160 kills credited to Kyle are more than for any sniper in American history, but the Navy SEAL told D Magazine that he wished instead that he could have calculated the number of people he saved. “That’s the number I’d care about,” he said. “I’d put that everywhere.”

After Kyle’s initial deployment to Iraq in 2003, he returned to fight in Fallujah in 2004, Ramadi in 2006 and Baghdad in 2008. On each tour of duty, the fighting grew fiercer and Kyle’s job grew harder. Insurgents who once carried guns now toted rocket-propelled grenades. Kyle still proved a skilled marksman even killing an enemy fighter 1.2 miles—or 21 football fields—away on a single shot.

When Kyle’s wife, Taya, told him their marriage could be over if he re-enlisted, the sniper reluctantly left the Navy with an honorable discharge in 2009 after a decade of service. He had earned a pair of Silver Stars and five Bronze Stars after surviving two gunshot wounds and six IED attacks.

“I loved what I did. If circumstances were different—if my family didn’t need me—I’d be back in a heartbeat,” Kyle wrote in his autobiography. “I had the time of my life being a SEAL.” Kyle struggled with the transition to civilian life in his roles as husband and father to his two young children. He found that although he left the war, the war didn’t leave him. He drank heavily, suffered bouts of depression and stopped working out.

Kyle felt anchorless without a mission and the camaraderie of his fellow SEALs. But he discovered a new call to duty by helping ailing veterans suffering from the physical and psychological scars of war. After seeing the therapeutic benefits of exercise in his own life, he helped to create the FITCO Cares Foundation in 2011 to provide exercise equipment and counseling to veterans. The following year he published “American Sniper,” which became a New York Times bestseller and the basis for the blockbuster film. Kyle donated his share of the book profits to families of colleagues who had died in battle and to a charity to help wounded veterans.

Kyle’s final mission to help his fellow veterans would tragically be his last. The former Navy SEAL often brought troubled veterans along with him to shoot at targets as a way for them to better connect. On February 2, 2013, he invited Eddie Ray Routh, a 25-year-old Marine veteran who had served in Iraq and Haiti, to a shooting range in Glen Rose, Texas. Routh, who reportedly suffered from post-traumatic stress disorder, allegedly shot and killed the 38-year-old Kyle and his friend Chad Littlefield at point-blank range.

To accommodate the mourners, Kyle’s funeral was held inside the Dallas Cowboys football stadium, where the veteran’s flag-draped coffin rested on the 50-yard line. For miles on end, crowds lined the route of the funeral procession to say goodbye to an American soldier who had survived years of combat only to be gunned down in the country he served to protect.