Officers attended the scene at a remote south Texas ranch, near to the Mexico border, in early January, finding the two men bleeding from gunshot wounds. A second guide was involved in the incident, but escaped without injury.
The casualties, guide Walker Daughtery, 26, and client Edwin Roberts, 59, and the other guide, Michael Bryant, told police they suspected the shooters were undocumented immigrants they had seen on the ranch earlier in their trip.
Their story was shared thousands of times online after Texas Commissioner of Agriculture and Donald Trump ally Sid Miller wrote about it on Facebook.
But police and a grand jury have now concluded the men were lying about the incident, and actually shot each other.
Investigators believe that Mr Daughtery became paranoid that illegal immigrants were inside a vehicle with Mr Roberts and his wife and attempted to get inside without saying anything, prompting Mr Roberts to shoot at the door.
Mr Daughtery then ran back to his cabin to grab his gun and to get backup from Mr Bryant, and together they opened fire on the truck.
Mr Daughtery and Mr Roberts were both struck by bullets, to the chest and to the arm respectively. It is believed that Mr Daughtery shot Mr Roberts, his client, and Mr Bryant shot Mr Daughtery, his colleague.
Police told news channel CBS 7 they are conducting ballistic testing to determine which guns fired which bullets, but they cannot test the bullet that struck Mr Daughtery as it is too close to his heart to be safely removed.
Mr Daughtery and Mr Bryant have both been indicted on third-degree felony charges, punishable by up to five years in prison.
After the alleged attack, a family friend setup a GoFundMe page stating that Mr Daughtery and his group were involved in a shoot-out with some illegal immigrants that were trying to steal his RV with his clients still inside it.
The appeal, to help pay for Mr Daughtery's medical bills as he is uninsured, raised over $26,000 (more than £20,000) before it was shut down.
Mr Daughtery's fiancée, who was at the ranch on the night of the shooting, told CBS 7 she could not comment on the case until it was completed, but said the couple had had multiple encounters with undocumented immigrants in the past month. She claimed they had had hundreds of dollars'-worth of supplies stolen by them from the ranch.
Although the area is well known for undocumented migrants from Mexico crossing over the border, Presidio County Sheriff Danny Dominguez said he had never seen violence like the alleged incident before. He said he was sceptical of the story from the beginning, and suggested the hunters were paranoid.
He told CBS 7: “I mean border patrol are experts in tracking in this area, we trust what they say because that’s all they do on a daily basis, and they didn’t find no sign, no indication that there was anybody in or out of that area that night.
“By the looks of it right now, we believe that during the shooting, with all the commotion and confusion going on, we believe that Michael shot Walker and Walker had shot Edwin,” Mr Dominguez added.
Mr Dominguez added that it took emergency services nearly two hours to arrive at the remote ranch, but fortunately one of the men’s wives was a nurse and was able to keep both men from bleeding out.
He said he wants ranchers and residents in the area to know they have nothing to fear at this time "regarding any violence from across the border".
Mr Miller, who became infamous in the US during last year’s election campaign when he called Democrat candidate Hillary Clinton a "c***" in a Tweet, deleted his initial Facebook post about the incident after police said they were suspicious of the hunters’ story.
Mr Miller’s initial post included two pictures of Mr Daugherty, one of which showed him in his hospital bed.
“The aliens were ambushing the RV that Walker and his wife. He was shot while trying to protect his hunters from the attack. Walker is a man of God and is now a hero,” Mr Miller wrote.
“This is why we need the wall and to secure our borders,” he added, in the post.
In addition to criticising the commissioner for spreading "fake news" people commenting on social media and local news outlets declared it ironic that it was actually paranoia about border security, not a lack of border security, that appears to have landed the two men in hospital.
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