WASHINGTON - Iraq veteran and ex-US Navy seal Chris Kyle, known as the deadliest sniper in US history, has been shot dead on a Texas shooting range.
Kyle, 38, wrote the 2012 bestseller American Sniper, about the psychology of a sniper, in which he said that he had killed more than 250 people.
He served four tours of duty in Iraq and was decorated for bravery. The gunman opened fire at about 15:30 local time (21:30 GMT) then fled in a pick-up truck belonging to one of the victims, local media reported.
Erath County Sheriff Tommy Bryant said the motive for the killings was unclear, and was unable to explain how the two men were shot.
Scott McEwen, who co-authored the book with Kyle, said: "It just comes as a shock and it's staggering to think that after all Chris has been through, that this is how he meets his end, because there are so many ways he could have been killed."
Kyle, a former cowboy, is regarded as the most prolific sniper the US has ever seen. Official Pentagon figures say he killed 160 people, but he estimated the total was 255.
According to army intelligence, he was nicknamed ‘The Devil’ by Iraqi insurgents, who put a $20,000 bounty on his head.
He appeared to show little remorse for his victims. "Every person I killed I strongly believe that they were bad," he told the BBC in an interview a year ago. "When I do go face God there is going to be lots of things I will have to account for but killing any of those people is not one of them."
A suspect, identified as Eddie Ray Routh, was arrested, according to reports.
Rough Creek Lodge is located in Glen Rose, Texas, which is about 50 miles southwest of Fort Worth. Rough Creek Lodge referred calls to the Erath County Sheriff's Office but Bryant was not immediately available for comment.
Kyle served four combat tours of duty in Operation Iraqi Freedom and elsewhere, and won two Silver Stars and five Bronze Stars for bravery, according to his book.
After leaving the Navy, Kyle founded Craft International, a firm that provided combat and weapons training to military, police, corporate and civilian clients.
In a 2012 interview with Time magazine he was asked what went through his mind when he aimed at a target.
"The first time, you're not even sure you can do it," he said. "But I'm not over there looking at these people as people. I'm not wondering if he has a family. I'm just trying to keep my guys safe. Every time I kill someone, he can't plant an IED. You don't think twice about it."
Kyle is the co-author of another book coming out in May under the title ‘American Gun - A History of the US in Ten Firearms." For the book he fired 10 weapons - such as the Spencer repeating rifle from the Civil War, the Colt .45 used in the Old West and the Thompson sub-machine gun popular with law enforcement and gangsters in the 1920s - and discussed their parts in US history.
In the wake of the slayings of 20 children and six adults at a school in Newtown, Connecticut in December, Kyle was interviewed in January about rising calls for curbing gun violence in the United States. He told the website guns.com that he favoured arming teachers who have been screened and trained and spoke against restrictions on gun owners.