BISBEE — Initial reports indicated that three U.S. Border Patrol agents were ambushed during a shooting on Oct. 2 in an area of the desert in southern Cochise County, although the incident was later determined to be "friendly fire."

The agents were responding to an activated sensor south of Highway 80 near mile marker 352, about five miles north of the U.S.-Mexico border and about seven miles east of Bisbee. The shooting took place at about 1:30 a.m.

Agend Nicholas Ivie, 30, was fatally shot. Another male agent received serious but non-life threatening injuries to his leg and buttocks. He was airlifted to a Tucson hospital for surgery, and he was later released. A female agent was unharmed.

According to reports released by the Sheriff’s Office on the Friday immediately following the incident, Border Patrol officials thought "the gunfire was from an apparent ambush and was not an AD [accidental discharge]."

After becoming aware of this information, one responding deputy reportedly put on his SWAT vest and load bearing vest, "which is capable of defeating rifle rounds where the appropriate plates are located." He also grabbed his AR 15 and three additional 30 round magazines.

This particular deputy and a Border Patrol agent who were hiking on trails toward the area of the incident located shoe impressions heading south/west from the scene. One shoe impression that was the most obvious in rocky terrain is commonly described as a "thicker running W" type pattern.

During the investigation at the scene, officials conducted an initial sweep, starting at the southeast corner and proceeding west. A second pass, from west to east, covered the middle area. And a final pass, from east to west, covered the northern region.

In the southern third of the scene, officials observed a heavily used trail running north/south which passes through the middle of the saddle, a lesser used and possibly older trail running southwest/northeast up to the saddle, and multiple items consistent with smuggling, such as empty drink bottles, food wrappers and empty metal containers.

The middle third of the scene also contained empty drink bottles, food wrappers and empty metal containers. Some of them appeared fresh as the bottles contained liquid/condensation and the wrappers showed no signs of exposure to the elements.

Officials also found "several shoe prints that they were not able to positively identify as belonging to a responder. One print was of higher interest as it appeared to be of a type of shoe, based on sole pattern, not associated with any type of footwear worn by responding personnel," according to a report.

Also, three areas of the ground on top of the saddle appeared to have indentations which are consistent with marks made by "double bundles" of marijuana. These bundles are commonly used by smugglers in this area, who commonly rest in saddles. Each location also had a long stick apparently used as markers for hidden bundles.

The northern third of the scene also contained "fresh" drink bottles and food wrappers, as well as empty metal containers. Also, agent Ivie’s body was found in this region. And two Mexican coins that did not show signs of weathering were found near some bullet casings, according to a report.

Following the shooting, many officials were looking for suspects in the area, with some reportedly doing roving patrols along Highway 80 in the vicinity as authorities thought that people involved could attempt to cross the road. Other officials were reportedly searching by aircraft and on foot.

However, on Oct. 5, the Federal Bureau of Investigation and the Sheriff’s Office announced that there are strong preliminary indications that the death of Ivie was the result of an accidental shooting or "friendly fire" and that the incident involved only the agents.