CHEYENNE, Wyo. - A June shooting that left one man dead in eastern Laramie County has been ruled self-defense, according to the Laramie County Sheriff’s Office.

Deputies responded around 4:22 p.m. June 24 to a report of a disturbance involving gunfire in the 1200 block of County Road 157. Investigators say the incident began earlier in the day after Christine Hefley moved horses from her shared property with Kevin Hefley to Patrick Gross’s property, upsetting Kevin.

Authorities say Kevin Hefley and Patrick Gross had a history of conflict. On the morning of the shooting, Hefley reportedly sent Gross a threatening text message. Later that day, Hefley allegedly drove toward Gross at a high speed. Gross fired at Hefley’s radiator in an attempt to stop the vehicle, but crash reconstruction showed Hefley hit Gross’s truck at about 60 mph - an act investigators say constituted the use of deadly force.

According to the sheriff’s office, Hefley exited his vehicle and began punching Gross, who was still inside his truck. Gross then shot Hefley, who continued attacking before collapsing from his injuries.

A forensic review included crash reconstruction, phone and social media analysis and toxicology testing, which showed Hefley’s blood alcohol content was nearly twice the legal limit at .143.

After a comprehensive review, the Laramie County District Attorney determined Gross acted in self-defense under Wyoming Statute 6-2-602, which allows the use of reasonable or deadly force when facing an imminent threat of serious injury or death. The law also states there is no duty to retreat.

No charges will be filed against Gross.