The incident, which is being called a “freak accident” by a witness, took place on the Lewis Trail Loop in the Weldon Spring Conservation area in St. Charles County.

Officers from the St. Charles County Police say they responded to a call to dispatchers around noon on Saturday and arrived on the scene at the Conservation area on Highway 94 roughly 30 minutes later.

Medical first responders used all-terrain vehicles to access the injured hiker, who has just now been identified by police as 47-year-old James Cay of O’Fallon, Missouri, and eventually employed a helicopter to airlift him to a nearby hospital. He was in serious condition after being shot in the chest.

The hunter, who has only just been identified by police as Mark A. Polson, 58, of Arnold, Missouri said he “mistook the man for a turkey,” according to KSDK local news, an NBC News affiliate before he accidentally shot him in the chest with a rifle.

The shooting took place during a turkey hunting event organized by the Missouri Department of Conservation, according to KSDK. The event was scheduled to end at about 1 pm, just around one hour after the unidentified hiker was shot. Sunday was the last official day of the turkey hunting season in Missouri.

“It’s so sad,” witness, Rebecca Brown who was running on the trail at the time told The St. Louis Post-Dispatch. She explaining that she saw Cay laid out on a stretcher covered in a yellow tarp and looking unresponsive, while he was being tended to by first responders. She also said a man, dressed in camouflage, presumably Polson, stood nearby.

Nancy Phillips of St. Louis told KSDK that she regularly hikes along the Lewis Trail loop, where the man was shot.

“This is a freak accident, I think. I always purposely wear my bright colors, so no hunters mistake me for anything,” she said.

Official turkey hunter safety and ethics rules obtained by the KSDK news team show that Polson, while operating within an approved turkey hunt zone and time, may not have followed necessary and required precautions:

Hunters must positively identify a turkey before aimingNever identity a turkey by—or shoot at—sound or movementIdentify what lies beyond any turkey in your sight because other hunters could be beyond the targetHunters involved in an accident are required by law to give assistance and identify themselves

If hunters do not follow the last rule, that could be a felony.

Val Joyner, a spokeswoman for the St. Charles County Police Department, told The St. Louis Post-Dispatch that Polson is cooperating with police.

Newsweek reached out to the St. Charles County Police for comment and will update the story with any response.